DE102022212904A1 - Individual mirror of a facet mirror of an illumination optics of a projection exposure system - Google Patents

Abstract

An individual mirror (20) for a facet mirror (13, 14) of an illumination optics (4) of a projection exposure system (1) has an actuator device (31) for pivoting the individual mirror (20) and a sensor device (41) for detecting the pivoting on, wherein the actuator device (31) and the sensor device (41) have rotational symmetries with different counts.

Description

The invention relates to an individual mirror of a facet mirror of an illumination optics of a projection exposure system as well as a facet module with a plurality of such individual mirrors and a field facet mirror for an illumination optics. The invention further relates to lighting optics and a lighting system for a projection exposure system and to a projection exposure system with such lighting optics. Finally, the invention relates to a method for producing a micro- or nanostructured component.

From the DE 10 2015 204 874 A1 Pivotable individual mirrors are known for a facet mirror of an illumination optics of a projection exposure system. There is a constant need to improve such individual mirrors, modules with such mirrors, lighting optics for projection exposure systems and projection exposure systems.

These tasks are solved by the objects of the present invention.

According to one aspect, an individual mirror of a facet mirror of an illumination optics of a projection exposure system has a reflection surface, an actuator device for pivoting the individual mirror and a sensor device for detecting the pivoting position of the individual mirror, wherein the sensor device and the actuator device and / or the Sensor device and the reflection surface of the individual mirror or the substrate on which the reflection surface is formed each have rotational symmetries with different counts.

The term “individual mirror” refers to the entire component comprising the actual mirror as well as its mounting and the electrical/electronic components for controlling or regulating the pivoting position.

A single mirror forms a special case of an optical component. Instead of a single mirror, this can also be formed by a lens, in particular a micro lens, or a diffractive component. In this case, the optically effective surface, in particular the beam-guiding and/or the beam-shaped surface, takes the place of the reflection surface.

According to the invention, it was recognized that it can lead to different advantages if the sensor device and the actuator device and/or the sensor device and the reflection surface of the individual mirror have different rotational symmetry properties. This will be explained in more detail below.

According to one aspect, the reflection surface of the individual mirror can be hexagonal. In particular, it can be designed as a regular, equilateral hexagon or as an irregular hexagon.

A hexagonal design has proven to be particularly advantageous for tiling the mirror surface of the facet mirror with as few gaps as possible.

The individual mirrors can in particular be micromirrors.

The reflection surface of the individual mirrors can in particular have a maximum diameter of at most 10 mm, in particular at most 5 mm, in particular at most 3 mm, in particular at most 2 mm, in particular at most 1 mm.

The individual mirror is in particular an individual mirror for a field facet mirror of an illumination optics of a projection exposure system.

It can also be an individual mirror for a pupil facet mirror of an illumination optics of a projection exposure system.

The individual mirror can in particular have a reflection surface, the shape of which enables a tiling, in particular a monohedral tiling, of the plane.

According to one aspect, the actuator device has threefold rotational symmetry.

Three-fold generally includes a 3-fold (m integer) rotational symmetry, that is, in particular, a six-fold one. The actuator device can in particular also have six-fold rotational symmetry.

The individual segments of the actuator device can be controlled independently of one another.

The symmetry properties of the actuator device can be adapted in particular to the symmetry properties of the reflection surface of the individual mirror. The reflection surface and the actuator device can in particular have rotational symmetries whose counts are integer multiples of each other. In particular, they can have identical rotational symmetries.

This can make the structural design of the individual mirror easier.

The segments of the actuator device can in particular be aligned along the diagonal of the individual mirror or its substrate or along the bisector of the reflection surface of the individual mirror or its substrate. They can also be rotated through an angle, for example 30°, 45° or 60°, aligned with the diagonals or the bisectors of the reflection surface of the individual mirror or its substrate.

According to one aspect, the sensor device has two-fold rotational symmetry.

Two-fold generally includes a 2n-fold (n integer) rotational symmetry, that is, in particular, a four-fold radial symmetry. The sensor device can in particular have four-fold rotational symmetry.

The sensor device can in particular have a rotational symmetry which is adapted to the geometric properties of the object field, in particular the symmetry properties of the same, in particular its rotational symmetry. The object field and the sensor device can in particular have identical rotational symmetry properties. In this regard, it was recognized that what is particularly important for detecting the pivoting position of the individual mirror is its effect on the image of the individual mirror into the object field.

According to a further aspect, the electrodes of the sensor device and/or the actuator device can each be differentially connected in pairs. In particular, it is possible to arrange a further electrode in mirror symmetry to one or more, in particular all, of the electrodes of the sensor device and/or the actuator device in mirror symmetry to the intersection of the two pivot axes of the individual mirror. These two electrodes can each be differentially connected to one another.

According to a further aspect, the mounting of the individual mirror has a cardan joint with two pivot axes running transversely to the surface normal. The pivot axes can in particular be perpendicular to one another. They can be formed, for example, by leaf springs.

In general, the bearing can have a solid joint.

The pivot axes and the solid-state joint can lie in the same plane.

The pivot axes can be arranged in the area of the reflection surface. They can also be faulty, in particular arranged below or below the reflection surface.

According to one aspect, the actuator device and/or the sensor device has a plurality of comb electrodes with comb fingers extending radially to the surface normal of the reflection surface of the individual mirror. The comb fingers can in particular each be arranged in a plane running radially to the surface normal.

The comb fingers can in particular be arranged in one, two or more ring areas.

The comb fingers can in particular be arranged in two or more concentrically arranged ring areas. Here, one ring area can include the electrodes of the sensor device, while another ring area includes the electrodes of the actuator device. An intermittent arrangement of electrodes of the sensor device and the actuator device in one and the same ring area is also possible.

The arrangement of the electrodes of the actuator device and the sensor device in separate ring areas means that their design and arrangement are essentially independent of one another. In addition, unwanted couplings between the actuator electrodes and the sensor electrodes can be reliably avoided.

The ring areas can be arranged concentrically to one another.

Three, four or more ring areas with electrodes of the sensor and/or actuator device can also be provided.

The electrodes of the sensor device can be arranged in particular in the inner ring area. In particular, they can be arranged in an area that is electrically shielded from the outside.

The electrodes of the actuator can be arranged in particular in the outer ring area.

Alternative arrangements of the sensor and/or actuator electrodes are possible.

A facet module for a facet mirror of an illumination optics of a projection exposure system has a plurality of individual mirrors according to the previous description, the individual mirrors being arranged in the manner of a regular tiling.

The distance between adjacent individual mirrors is preferably in the range of at most 100 μm, in particular at most 50 μm, in particular at most 30 μm, in particular at most 20 μm, in particular at most 10 μm.

The distance between adjacent individual mirrors can preferably be at most 1/10, in particular at most 1/20, in particular at most 1/25 of the side length of the individual mirrors.

According to one aspect, the facet module itself is designed such that it forms a tile for monohedral regular tiling of a plane.

The facet module can have a smooth edge. In particular, it can be designed to be strictly convex.

The facet module can also have a jagged edge. Here, the edge of the facet module can follow the edge of the individual mirrors in sections.

The facet module can have 7, 19, 31, 331 or more individual mirrors. It can in particular have over 100, in particular over 1000, in particular over 10,000 individual mirrors. Typically, the number of individual mirrors in the facet module is a maximum of one million.

According to one aspect, the facet module can have a pivoting range of the individual mirrors of at least 120 mrad about each of the pivot axes and a fill factor of at least 91%. This represents a significant improvement over previously known facet modules.

A field facet mirror for an illumination optics of a projection exposure system has a plurality of individual mirrors according to the preceding description and/or a plurality of facet modules according to the preceding description.

Here, a plurality of individual mirrors can form a virtual facet, that is, can be connected together to form a cassette or a part of it.

An illumination optics for a projection exposure system comprises a field facet mirror according to the previous description and a pupil facet mirror, by means of which the field facets of the field facet mirror can be imaged into an object field.

According to one aspect, the facet modules of the field facet mirror are arranged such that the edge contours of the individual mirrors enclose an angle with a scanning direction of at least 10°, in particular at least 20°, in particular at least 30° when imaging into the object field.

In the case of individual mirrors in the form of regular hexagons, the angles of their sides with the scanning direction can be 90°, 30° and -30°, respectively.

Orienting the individual mirrors in such a way that their edge contours are not imaged into the object field parallel to the scanning direction has proven to be particularly advantageous for the homogeneous illumination of the object field.

An illumination system for a projection exposure system has, in addition to illumination optics according to the previous description, a radiation source for generating illumination radiation. The radiation source can in particular be an EUV radiation source, that is to say a radiation source for generating illumination radiation in the EUV range, in particular in the wavelength range of less than 13.5 nm.

An optical system for a projection exposure system has, in addition to illumination optics according to the previous description, projection optics for imaging a reticle arranged in the object field into an image field.

A projection exposure system for microlithography has illumination optics according to the previous description, a radiation source for generating illumination radiation and projection optics for imaging a reticle arranged in the object field into an image field.

The radiation source can in turn be an EUV radiation source.

A projection exposure system is provided to produce a micro- or nanostructured component. A reticle with structures to be imaged is then arranged in the object field and the reticle is imaged onto a radiation-sensitive layer of a wafer arranged in the image field.

• 1 eine schematische Darstellung einer Projektionsbelichtungsanlage und ihrer Bestandteile,
• 2 eine schematische Darstellung eines optischen Bauelements mit einer Aktuator- und einer Sensoreinrichtung,
• 3 eine alternative Darstellung des optischen Bauelements gemäß 2 bei welcher der Spiegelkörper mit den daran angeordneten Gegenelektroden bzw. Abschirm-Elementen zur Seite geklappt ist,
• 4 schematisch einen Horizontalschnitt durch eine Ausführung eines optischen Bauelements zur Verdeutlichung einer möglichen Anordnung der Elektroden einer Aktuator- und einer S ensor-Einrichtung,
• 5 schematisch die Anordnung von unterschiedlichen Sensor- und Aktuator-Bereichen relativ zu einem optischen Bauelement in Form eines Einzelspiegels mit einer sechseckigen Reflexionsfläche,
• 6 eine Darstellung wie 5 einer Alternative,
• 7 eine Darstellung wie 5 gemäß einer weiteren Alternative,
• 8 schematisch eine Draufsicht auf die Reflexionsflächen eines Spiegel-Arrays gemäß einer Variante,
• 9 schematisch eine Draufsicht auf die Reflexionsflächen eines Spiegel-Arrays gemäß einer weiteren Variante,
• 10 schematisch eine Draufsicht auf die Reflexionsflächen eines Spiegel-Arrays gemäß einer weiteren Variante,
• 11 schematisch eine Draufsicht auf die Reflexionsflächen eines Spiegel-Arrays gemäß einer weiteren Variante,
• 12 schematisch eine Aufstellung eines Spiegel-Arrays mit einer Mehrzahl von modularen Spiegel-Arrays gemäß einer Variante,
• 13 schematisch eine Aufstellung eines Spiegel-Arrays mit einer Mehrzahl von modularen Spiegel-Arrays gemäß einer weiteren Variante und
• 14 schematisch eine Aufstellung eines Spiegel-Arrays mit einer Mehrzahl von modularen Spiegel-Arrays gemäß einer weiteren Variante.

Further details and advantages of the invention result from the description of exemplary embodiments using the figures. Show it:

• 1 a schematic representation of a projection exposure system and its components,
• 2 a schematic representation of an optical component with an actuator and a sensor device,
• 3 an alternative representation of the optical component according to 2 in which the mirror body with the counter electrodes or shielding elements arranged on it is folded to the side,
• 4 schematically a horizontal section through an embodiment of an optical component to illustrate a possible arrangement of the electrodes of an actuator and a sensor device,
• 5 schematically the arrangement of different sensor and actuator areas relative to an optical component in the form of an individual mirror with a hexagonal reflection surface,
• 6 a representation like 5 an alternative,
• 7 a representation like 5 according to another alternative,
• 8th schematically a top view of the reflection surfaces of a mirror array according to a variant,
• 9 schematically a top view of the reflection surfaces of a mirror array according to a further variant,
• 10 schematically a top view of the reflection surfaces of a mirror array according to a further variant,
• 11 schematically a top view of the reflection surfaces of a mirror array according to a further variant,
• 12 schematically a setup of a mirror array with a plurality of modular mirror arrays according to a variant,
• 13 schematically a setup of a mirror array with a plurality of modular mirror arrays according to a further variant and
• 14 schematically a setup of a mirror array with a plurality of modular mirror arrays according to a further variant.

First, the general structure of a projection exposure system 1 and its components are described. For details on this see the WO 2010/049076 A 2 and the WO 2016/146 541 A1 referred to, which is hereby fully integrated into this application as part of the present application. The description of the general structure of the projection exposure system 1 is to be understood exclusively as an example. It serves to explain a possible application of the subject matter of the present invention. The subject matter of the present invention can also be used in other optical systems, in particular in alternative variants of projection exposure systems.

1 shows schematically in a meridional section a projection exposure system 1 for microlithography. An illumination system 2 of the projection exposure system 1 has, in addition to a radiation source 3, illumination optics 4 for illuminating an object field 5 in an object plane 6. The object field 5 can be rectangular or arcuate with an x/y aspect ratio of, for example, 13/1. What is exposed here is an object arranged in the object field 5 and in the 1 Reflective reticle, not shown, which carries a structure to be projected with the projection exposure system 1 for producing micro- or nanostructured semiconductor components. A projection optics 7 is used to image the object field 5 into an image field 8 in an image plane 9. The structure on the reticle is imaged on a light-sensitive layer of a wafer arranged in the area of the image field 8 in the image plane 9, which is not shown in the drawing.

The reticle, which is held by a reticle holder, not shown, and the wafer, which is held by a wafer holder, not shown, are scanned synchronously in the y-direction during operation of the projection exposure system 1. Depending on the imaging scale of the projection optics 7, the reticle can also be scanned in opposite directions relative to the wafer.

The radiation source 3 is an EUV radiation source with emitted useful radiation in the range between 5 nm and 30 nm. It can be a plasma source, for example a GDPP source (gas discharge produced plasma), or an LPP source (laser produced plasma). Other EUV radiation sources, for example those based on a synchrotron or a free electron laser (FEL), are also possible.

EUV radiation 10, which emanates from the radiation source 3, is focused by a collector 11. A corresponding collector is, for example, from the EP 1 225 481 A2 known. After the collector 11, the EUV radiation 10 propagates through an intermediate focus plane 12 before hitting 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 field facet mirror 13 can be arranged at a distance from a plane conjugate to the object plane 6. In this case it is generally referred to as the first facet mirror.

The EUV radiation 10 is also referred to below as useful radiation, illumination radiation or imaging light.

After the field facet mirror 13, the EUV radiation 10 is reflected by a pupil facet mirror 14. The pupil facet mirror 14 lies either in the entrance pupil plane of the projection optics 7 or in a plane optically conjugate thereto. It can also be arranged at a distance from such a plane.

The field facet mirror 13 and the pupil facet mirror 14 are constructed from a large number of individual mirrors, which will be described in more detail below. The division of the field facet mirror 13 into individual mirrors can be such that each of the field facets, which themselves illuminate the entire object field 5, is represented by exactly one of the individual mirrors. Alternatively, it is possible to build up at least some or all of the field facets using a plurality of such individual mirrors. The same applies to the design of the pupil facets of the pupil facet mirror 14 assigned to the field facets, which can each be formed by a single individual mirror or by a plurality of such individual mirrors.

The EUV radiation 10 impinges on the two facet mirrors 13, 14 at a defined angle of incidence. The two facet mirrors are used in particular in the area of normal incidence operation, i.e. H. with an angle of incidence that is less than or equal to 25 ° to the mirror normal, exposed to the EUV radiation 10. Impaction under grazing incidence is also possible. The pupil facet mirror 14 is arranged in a plane of the illumination optics 4, which represents a pupil plane of the projection optics 7 or is optically conjugate to a pupil plane of the projection optics 7. With the aid of the pupil facet mirror 14 and an imaging optical assembly in the form of transmission optics 15 with mirrors 16, 17 and 18 designated in the order of the beam path for the EUV radiation 10, the field facets of the field facet mirror 13 are imaged in the object field 5 in a superimposed manner. The last mirror 18 of the transmission optics 15 is a mirror for grazing incidence (“grazing incidence mirror”). The transmission optics 15, together with the pupil facet mirror 14, are also referred to as follow-up optics for transferring the EUV radiation 10 from the field facet mirror 13 to the object field 5. The illumination light 10 is guided from the radiation source 3 to the object field 5 via a plurality of illumination channels. Each of these illumination channels is assigned a field facet of the field facet mirror 13 and a pupil facet of the pupil facet mirror 14 arranged downstream of this. The individual mirrors of the field facet mirror 13 and the pupil facet mirror 14 can be actuatorically tilted, so that a change in the assignment of the pupil facets to the field facets and a corresponding changed configuration of the illumination channels can be achieved. Different lighting settings result, which differ in the distribution of the illumination angles of the illumination light 10 over the object field 5.

To make it easier to explain positional relationships, a global Cartesian xyz coordinate system is used below, among other things. The x-axis runs in the 1 towards the viewer perpendicular to the plane of the drawing. The y-axis runs in the 1 To the right. The z-axis runs in the 1 up.

Different lighting settings can be achieved by tilting the individual mirrors of the field facet mirror 13 and a corresponding change in the assignment of these individual mirrors of the field facet mirror 13 to the individual mirrors of the pupil facet mirror 14. Depending on the tilting of the individual mirrors of the field facet mirror 13, the individual mirrors of the pupil facet mirror 14 newly assigned to these individual mirrors are tracked by tilting in such a way that an image of the field facets of the field facet mirror 13 in the object field 5 is again ensured.

Further aspects of the lighting optics 4 are described below.

The one field facet mirror 13 in the form of a multi- or micromirror array (MMA) forms an example of an optical assembly for guiding the useful radiation 10, i.e. the EUV radiation bundle. The field facet mirror 13 is designed as a microelectromechanical system (MEMS). It has a large number of individual mirrors 20 arranged in rows and columns in a mirror array 19 in a matrix-like manner. The mirror arrays 19 are designed to be modular. You can use one as a base plate trained support structure can be arranged. Essentially any number of mirror arrays 19 can be arranged next to one another. The total reflection surface, which is formed by the entirety of all mirror arrays 19, in particular their individual mirrors 20, can therefore be expanded as desired. The mirror arrays are designed in particular in such a way that they enable a plane to be tiled essentially without gaps. The ratio of the sum of the reflection surfaces 26 of the individual mirrors 20 to the total area covered by mirror arrays 19 is also referred to as the integration density. This integration density is in particular at least 0.5, in particular at least 0.6, in particular at least 0.7, in particular at least 0.8, in particular at least 0.9.

The mirror arrays 19 are fixed on the base plate using fixing elements 29. For details see, for example, the WO 2012/130768 A2 referred.

The individual mirrors 20 are designed to be actuatorically tiltable, as will be explained below. In total, the field facet mirror 13 has approximately 100,000 of the individual mirrors 20. Depending on the size of the individual mirrors 20, the field facet mirror 13 can also have a different number of individual mirrors 20. The number of individual mirrors 20 of the field facet mirror 13 is in particular at least 1000, in particular at least 5000, in particular at least 10,000. It can be up to 100,000, in particular up to 300,000, in particular up to 500,000, in particular up to 1000,000.

A spectral filter can be arranged in front of the field facet mirror 13, which separates the useful radiation 10 from other wavelength components of the emission from the radiation source 3 that cannot be used for projection exposure. The spectral filter is not shown.

The field facet mirror 13 is exposed to useful radiation 10 with a power of, for example, 840 W and a power density of 6.5 kW/m ² .

The entire individual mirror array of the facet mirror 13 has, for example, a diameter of 500 mm and is densely packed with the individual mirrors 20. To the extent that a field facet is realized by exactly one individual mirror, the individual mirrors 20 represent the shape of the object field 5, except for a scaling factor. The facet mirror 13 can consist of 500 individual mirrors 20, each representing a field facet, with a dimension in the range from approximately 5 mm to approximately 50 mm in the y-direction and in the range of about 100 mm to about 300 mm in the x-direction. As an alternative to realizing each field facet by exactly one individual mirror 20, each of the field facets can be approximated by groups of smaller individual mirrors 20. A field facet with dimensions of 5 mm in the y-direction and 100 mm in the x-direction can e.g. B. can be constructed using a 1 x 20 array of individual mirrors 20 with dimensions of 5 mm x 5 mm up to a 10 x 200 array of individual mirrors 20 with dimensions of 0.5 mm x 0.5 mm.

To change the lighting settings, the tilt angles of the individual mirrors 20 are adjusted. The tilt angles in particular have a displacement range of ± 50 mrad, in particular ± 100 mrad, in particular ± 150 mrad. When adjusting the tilt position of the individual mirrors 20, an accuracy of better than 0.2 mrad, in particular better than 0.1 mrad, is achieved.

The individual mirrors 20 of the field facet mirror 13 and the pupil facet mirror 14 when executing the lighting optics 4 after 1 wear multilayer coatings to optimize their reflectivity at the wavelength of the useful radiation 10. The temperature of the multilayer coatings should not exceed 425 K when operating the projection exposure system 1. This is achieved by a suitable structure of the individual mirrors 20. For details see DE 10 2013 206 529 A1 referred to, which is hereby fully integrated into the present application.

The individual mirrors 20 of the lighting optics 4 are housed in an evacuable chamber 21, from which in the 2 and 6 a boundary wall 22 is indicated. The chamber 21 communicates with a vacuum pump 25 via a fluid line 23, in which a shut-off valve 24 is accommodated. The operating pressure in the evacuable chamber 21 is a few Pascals, in particular 3 Pa to 5 Pa (partial pressure H ₂ ). All other partial pressures are well below 1 x 10 ^-7 mbar.

The mirror having the plurality of individual mirrors 20, together with the evacuable chamber 21, forms an optical assembly for guiding a bundle of EUV radiation 10.

Each of the individual mirrors 20 can have a reflection surface 26 with dimensions of 0.1 mm x 0.1 mm, up to 0.5 mm x 0.5 mm, up to 1.0 mm x 1.0 mm or even up to to 5 mm x 5 mm and larger. The reflection surface 26 can also have smaller dimensions. In particular, it has side lengths in the µm or lower mm range. The individual mirrors 20 are therefore also referred to as micromirrors. The reflection surface 26 is part of a mirror body 27 of the individual mirror 20. The mirror body 27 carries the multilayer coating.

With the help of the projection exposure system 1, at least part of the reticle is imaged onto an area of a light-sensitive layer on the wafer for the lithographic production of a micro- or nanostructured component, in particular a semiconductor component, e.g. a microchip. Depending on the design of the projection exposure system 1 as a scanner or as a stepper, the reticle and the wafer are synchronized in time and moved continuously in the y-direction in scanner mode or step by step in stepper mode.

The y direction is also called the scanning direction. The x direction is also called the cross scan direction.

Further details and aspects of the mirror arrays 19, in particular the optical components that comprise the individual mirrors 20, are described below.

First, with reference to the 2 until 3 a first variant of an optical component 30 with an individual mirror 20 and in particular the displacement device 31 for displacing, in particular for pivoting, the individual mirror 20, and a sensor device 41 for detecting the displacement position, in particular the pivoting position of the individual mirror 20, is described.

The representation according to 3 corresponds to the according 2 , where in the 3 the mirror body 27 of the individual mirror 20 is folded away to the side. This makes the structures of the displacement device 31 and the sensor device more visible.

The optical component includes the individual mirror 20, which is designed in particular as a micromirror. The individual mirror 20 includes the mirror body 27 described above, on the front of which the reflection surface 26 is formed. The reflection surface 26 is formed in particular by a multi-layer structure. In particular, it is radiation-reflecting for the illumination radiation 10, in particular for EUV radiation.

According to the variant shown in the figures, the reflection surface 26 is square, but is shown partially cut in order to also show the actuator system. It is generally rectangular. It can also be triangular or hexagonal. In particular, it is designed like a tile in such a way that a seamless tiling of a level with the individual mirrors 20 is possible. The individual mirror 20 is mounted by means of a joint 32, which will be described in more detail below. In particular, it is mounted in such a way that it has two degrees of tilting freedom. The joint 32 in particular enables the individual mirror 20 to be tilted about two tilting axes 33, 34. The tilting axes 33, 34 are perpendicular to one another. They intersect at a central intersection, which is referred to as the effective pivot point 35.

If the individual mirror 20 is in a non-pivoted neutral position, the effective pivot point 35 lies on a surface normal 36, which runs through a central point, in particular the geometric center of gravity of the reflection surface 26.

Unless otherwise stated, the direction of the surface normal 36 is always understood below to mean the direction of the surface normal in the non-tilted neutral position of the individual mirror 20.

The displacement device 31 will first be described in more detail below.

The displacement device 31 comprises an electrode structure with actuator electrodes, in particular in the form of actuator-transducer-stator electrodes 37; and actuator-transducer mirror electrodes 42. According to the in the 2 until 3 In the variant shown, the electrode structure includes four actuator-transducer-stator electrodes 37 ₁ , 37 ₂ , 37 ₃ and 37 ₄ . The number of actuator-transducer-stator electrodes 37; is generally at least 2. In particular, it can be 2, 3, 4, 6 or more (see 5 until 7 ).

All actuator transducer electrodes 37i, 42 are designed as comb electrodes with a plurality of comb fingers 38. The complementary comb fingers of the mirror and stator interlock. The combs of the individual actuator electrodes 37; each include 30 actuator converters stator comb fingers 38, which are also referred to below as stator comb fingers or simply as comb fingers. A different number is also possible. The number of comb fingers 38 of the actuator-transducer-stator electrodes 37; is in particular at least 2, in particular at least 3, in particular at least 5, in particular at least 10. It can be up to 50, in particular up to 100.

The combs of the actuator-transducer mirror electrodes 42 accordingly comprise actuator-transducer mirror comb fingers 43, which are also referred to below as mirror comb fingers or simply as comb fingers. The number of mirror comb fingers 43 corresponds to the number of stator comb fingers. It can also differ by one from the number of stator comb fingers.

The comb fingers 38 are arranged in such a way that they extend in the radial direction with respect to the surface normal 36 or the effective pivot point 35. According to a variant not shown in the figures, the comb fingers 38, 43 can also be arranged tangentially to circles around the effective pivot point 35. They can also have a design which corresponds to sections of concentric circular cylinder lateral surfaces around the surface normal 36.

All of the actuator-transducer-stator electrodes 37; are arranged on a support structure in the form of a substrate 39. In particular, they are arranged in a stationary manner on the substrate 39. In particular, they are arranged in a single plane defined by the front side of the substrate 39. This level is also referred to as the actuator level or the comb level.

A wafer in particular serves as substrate 39. The substrate 39 is also referred to as a base plate.

The actuator-transducer stator electrodes 37; are each arranged in an area on the substrate 39, which has an outer envelope on the one hand and an inner envelope on the other.

The outer envelope can be geometrically similar to the reflection surface 26.

The inner envelope can be circular.

Alternatively, the actuator-transducer-stator electrodes 37; also be arranged in an annular area on the substrate 39. The outer envelope is also circular. The individual actuator-transducer-stator electrodes 37; are in particular each arranged in annular section-shaped areas. The electrode structure as a whole, that is, all actuator-transducer-stator electrodes 37; are arranged in an area which has an outer envelope which just corresponds to that of the reflection surface of the individual mirror 20. It can also be arranged in a slightly smaller area, in particular approximately 5% to 25% smaller.

The electrode structure has rotational symmetry. In particular, it has two-fold, three-fold, four-fold or six-fold rotational symmetry. The electrode structure can also have a different rotational symmetry. In particular, it has a k-fold rotational symmetry, where k is the number of actuator-transducer-stator electrodes 37; indicates. Apart from the subdivision of the electrode structure into the different actuator-transducer-stator electrodes 37; the electrode structure has an n-fold rotational symmetry, where n is just the total number of comb fingers 38 of all actuator-transducer-stator electrodes 37; corresponds.

The individual actuator-transducer-stator electrodes 37; are designed identically apart from their different arrangement on the substrate 39. This is not absolutely necessary. They can also be designed differently. They can be designed in particular depending on the mechanical properties of the joint 32.

The comb fingers 38 are arranged radially to the effective pivot point 35, or radially to the alignment of the surface normal 36 in the non-pivoted neutral state of the individual mirror 20.

In the case of individual mirrors 20 whose mirror bodies 27 have dimensions of 1 mm x 1 mm, the comb fingers 38 have a thickness d of at most 5 μm at their outer end in the radial direction. In general, the maximum thickness d of the comb fingers 38 at their outer end in the radial direction is in the range from 1 μm to 20 μm, in particular in the range from 3 μm to 10 μm.

The comb fingers 38 have a height h, that is to say an extension in the direction of the surface normal 36, in the range from 10 μm to 200 μm, in particular in the range from 75 μm to 150 μm. Other values are also conceivable. The height h is constant in the radial direction. It can also decrease in the radial direction. This makes it possible to make larger tilt angles possible without causing the comb fingers of the actuator mirror electrode 42 to hit the base plate.

Adjacent comb fingers 38, 43 of the actuator electrodes 37; on the one hand and the actuator mirror electrodes 42 on the other hand, in the non-pivoted state of the individual mirror 20, have a minimum distance in the range of 1 µm to 10 µm, in particular in the range of 3 µm to 7 µm, in particular of approximately 5 µm. For individual mirrors 20 with smaller or larger dimensions, these values can be scaled accordingly.

This minimum distance is the minimum distance between adjacent mirror and stator comb fingers measured in the neutral, non-pivoted state of the individual mirror 20. When the individual mirror 20 is tilted, the comb fingers can approach one another. The minimum distance is chosen such that even if the individual mirror 20 is tilted to the maximum, there is no collision between adjacent mirror and stator comb fingers. Manufacturing tolerances are also taken into account here. Such skills Tolerances are a few micrometers, in particular at most 5 µm, in particular at most 3 µm, in particular at most 2 µm, in particular at most 1 µm.

The maximum possible approach of adjacent comb fingers 38, 43 can be determined in a simple manner from the geometric details of the same and their arrangement as well as the maximum possible tilting of the individual mirror 20. In the present embodiment, the maximum approach of adjacent comb fingers 38, 43 is approximately 2 μm when the individual mirror 20 is tilted by 100 mrad. The maximum approximation is in particular less than 10 µm, in particular less than 7 µm, in particular less than 5 µm, in particular less than 3 µm.

The actuator-transducer stator electrodes 37 _i each interact with an actuator mirror electrode 42. The actuator mirror electrode 42 is connected to the mirror body 27. The actuator mirror electrode 42 is in particular mechanically fixedly connected to the mirror body 27. The actuator-transducer mirror electrodes 42 form a counter electrode to the actuator-transducer stator electrodes 37i. They are therefore also simply referred to as counter electrodes.

The actuator mirror electrode 42 forms a passive electrode structure. This is understood to mean that the actuator mirror electrode 42 is subjected to a fixed, constant voltage.

The actuator mirror electrode 42 is complementary to the actuator transducer stator electrodes 37; educated. In particular, it forms a ring with actuator-transducer mirror comb fingers 43, which are also referred to below as mirror comb fingers or simply as comb fingers 43. The geometric properties of the mirror comb fingers 43 of the actuator mirror electrode 42 essentially correspond to the stator comb fingers 38 of the actuator converter stator electrodes _37i .

All of the comb fingers 38, 43 can have the same height h, i.e. H. have identical dimensions in the direction of the surface normal 36. This makes the manufacturing process easier.

The mirror comb fingers 43 of the actuator mirror electrode 42 can also have a different height in the direction of the surface normal 36 than the stator comb fingers 38 of the active actuator converter stator electrodes 37i.

The comb fingers 38, 43 can have a height h that decreases in the radial direction. It is also possible to make the comb fingers 38, 43 in the area of the corners of the optical component 30 shorter than the remaining comb fingers 38, 43. This allows a larger tilt angle of the individual mirror 20.

The actuator mirror electrode 42 is in particular designed such that one of the comb fingers 43 of the actuator mirror electrode 42 is in a space between two of the comb fingers 38 of the actuator transducer stator electrodes 37; can immerse.

The actuator mirror electrode 42 is electrically conductively connected to the mirror body 27. Your comb fingers 43 are therefore equipotential. The mirror body 27 is connected to the base plate with a low resistance via an electrically conductive joint spring. In principle, the mirror substrate, i.e. the mirror body 27, the actuator mirror electrodes 42 and sensor mirror electrodes 45 can also be individually electrically connected via separate supply lines via the solid-state joint 32 and thus, for example, set to different potentials or decoupled with regard to interference and/or crosstalk. The base plate can be on earth, but it doesn't have to be. Alternatively, the mirror can be connected to a voltage source via a conductive joint spring on another but be galvanically decoupled from the mirror plate. This makes it possible to apply a fixed or variable bias voltage to the mirror.

The actuator-transducer stator electrodes 37; can be supplied with an actuator voltage U _A to pivot the individual mirror 20. The actuator-transducer stator electrodes 37; are therefore also called active actuator-transducer-stator electrodes 37; designated. To actuate the actuator-transducer-stator electrodes 37; A voltage source, not shown in the figures, is provided with the actuator voltage U _A. The actuator voltage U _A is at most 200 volts, in particular at most 100 volts. By appropriately applying a selection of the actuator-transducer-stator electrodes 37; With the actuator voltage U _A, the individual mirror 20 can be tilted from a neutral position by up to 50 mrad, in particular up to 100 mrad, in particular up to 150 mrad. Alternatively, the actuators can also be controlled with a charge source (current source).

The different actuator-transducer-stator electrodes 37; can be applied with different actuator voltages U _Ai to pivot the individual mirror 20. A control device (not shown in the figures) is provided to control the actuator voltages U _Ai .

To tilt one of the individual mirrors 20, one of the actuator-transducer-stator electrodes 37; an actuator voltage U _A is applied. At the same time, a different actuator voltage U _A2 ≠ U _A1 is applied to the actuator-transducer stator electrode 37 _j , which is opposite the surface normal 36. Here U _A2 can be 0 volts. In particular, it is possible to use only one of the actuator-transducer-stator electrodes 37; with the actuator voltage U _A1 , while all other actuator-transducer-stator electrodes 37 _j are kept at a voltage of 0 volts.

When the individual mirror 20 is tilted, the comb fingers of the actuator mirror electrode 42 dip on one side, in particular in the area of the actuator transducer stator electrode 37 to which the actuator voltage U _A is applied; deeper between the comb fingers 38 of this actuator-transducer-stator electrode 37; a. On the opposite side of the tilt axis 33, the actuator mirror electrode 42 dips less deeply into the actuator converter stator electrodes _37j . The actuator mirror electrode 42 can even emerge from the actuator converter stator electrodes 37 _j at least in some areas.

The comb overlap, that is, the immersion depth of the actuator mirror electrode 42 between the actuator transducer stator electrodes 37; with a mirror dimension of approximately 0.5mm x 0.5mm in the neutral position of the individual mirror is 20 - 30 µm.

In the neutral position, a tilt of the mirror 20 by 100 mrad results in a maximum reduction in the distance between the comb fingers 43 of the actuator mirror electrode 42 and the comb fingers 38 of the actuator transducer stator electrodes 37; around 1.1 µm. The comb fingers 43 of the actuator mirror electrode 42 and the comb fingers 38 of the actuator transducer stator electrodes 37; are therefore spaced apart from one another in every pivoting position of the mirror 20, in particular without contact. The immersion depth, that is to say the ridge overlap, is chosen in particular in such a way that this is ensured.

According to an alternative, the comb fingers 38, 43 are somewhat shorter in the outer region and therefore have a smaller overlap, that is to say a smaller immersion depth. The immersion depth in the outermost area can, for example, be approximately half as large as the immersion depth in the inner area. This information also refers to the neutral position of the mirror 20.

By depending on the immersion depth of the comb fingers 38, 43 on their radial position, the characteristics, in particular the linearity of the actuation, can also be influenced. Since all of the actuator-transducer-stator electrodes 37; are arranged in a single level, the actuator level, complex, serial kinematics can be dispensed with. The displacement device 31 is characterized by parallel kinematics. The displacement device 31 in particular has no movably arranged active components. All of the actuator- _transducer -stator electrodes 37; are arranged immovably and stationary on the substrate 39. A sensor device 41 is provided to detect the pivoting position of the individual mirror 20. The sensor device 41 can form part of the displacement device 31.

The sensor device 41 includes sensor electrodes, in particular in the form of sensor transducer mirror electrodes 45 and sensor transducer stator electrodes _44i .

The sensor unit includes in particular four sensor converter stator electrodes 44 ₁ to 44 ₄ . The sensor converter stator electrodes 44i are simply referred to as sensor electrodes. The number of sensor transducer stator electrodes 44; can depend on the number of actuator-transducer-stator electrodes 37; differ.

The sensor transducer stator electrodes 44 ₁ to 44 ₄ are in the variant according to 2 until 3 each arranged along the diagonal of the substrate 39. At the in the 2 until 3 In the variant shown, the sensor transducer stator electrodes 44 ₁ to 44 ₄ are arranged offset by 45 ° relative to the tilt axes 33, 34 of the joint 32.

The actuator-transducer stator electrodes 37; are each arranged in quadrants 54 ₁ to 54 ₄ on the substrate 39. The sensor transducer stator electrodes 44i are each arranged in the same quadrant 54 ₁ to 54 ₄ as one of the actuator transducer stator electrodes 37i. The actuator device 31, in particular the arrangement and design of the actuator-transducer-stator electrodes 37; can have essentially the same symmetry properties as the reflection surface 26 of the individual mirror 20.

The sensor device 41, in particular the sensor transducer stator electrodes 44i, can have the same symmetry properties as the object field 5.

Preferably there are two sensor transducer stator electrodes 44; opposite each other with respect to the effective pivot point 35; differentially connected. However, such an interconnection is not absolutely necessary. General it is advantageous if two sensor electrodes 44i opposite each other with respect to the effective pivot point 35 are designed and arranged in such a way that they can be read out differentially.

The sensor transducer stator electrodes 44; are designed as comb electrodes. The sensor transducer stator electrodes 44i can in particular be designed corresponding to the actuator transducer stator electrodes 37i, the description of which is hereby referred to. The sensor transducer stator electrodes 44; each include a sensor transducer stator transmitter electrode 47, hereinafter also referred to as transmitter electrode, and a sensor transducer stator receiver electrode, hereinafter also referred to as receiver electrode, 48. Both the sensor transducer stator transmitter electrode 47 and the sensor transducer stator receiver electrode 48 have a comb structure. In particular, they include a plurality of comb fingers. The comb fingers of the sensor transducer stator transmitter electrode 47 are in particular arranged alternately to the comb fingers of the sensor transducer stator receiver electrode 48.

The sensor device 41 comprises for each of the sensor transducer stator electrodes 44; a sensor transducer mirror electrode 45. According to an advantageous embodiment, the sensor transducer mirror electrodes 45 each form a shielding unit for the sensor transducer stator electrodes 44i. The sensor transducer mirror electrode 45 each comprises comb elements with a plurality of comb fingers 46. The sensor transducer mirror electrode 45 is corresponding to a counter electrode suitable for the sensor transducer stator electrodes 44; educated. The sensor transducer mirror electrodes 45 can in particular be designed in accordance with the actuator transducer mirror electrodes 42, the description of which is hereby referred to.

The sensor transducer mirror electrodes 45 are each fixedly connected to the mirror body 27. They are arranged in the area of the diagonal of the mirror body 27. When the individual mirror 20 is tilted, the sensor transducer mirror electrode 45 can dip to different depths between the comb fingers of the sensor transducer stator electrodes 44i, in particular between the transmitter electrode 47 and the receiver electrode 48. This results in variable shielding of adjacent comb fingers, in particular in variable shielding of the receiver electrode 48 from the transmitter electrode 47. This leads to the capacitance between the adjacent comb fingers of the sensor transducer stator electrodes 44; when the individual mirror 20 is pivoted. The change in capacity can be measured. The inputs of a measuring device are used for this purpose, as shown schematically in 4 is shown alternating with the comb fingers of the sensor transducer stator electrodes 44; tied together.

The immersion depth of the sensor transducer mirror electrodes 45 between the sensor transducer stator electrodes 44i, in particular between the transmitter electrodes 47 and the receiver electrodes 48, is 20 μm to 40 μm. This ensures that the comb fingers 46 still have a residual immersion depth between the transmitter electrodes 47 and the receiver electrodes 48 everywhere, even in the maximum tilted pivoting position, that is, they never completely emerge. This ensures differential sensor operation over the entire tilting range. On the other hand, the immersion depth of the sensor-transducer mirror electrode 45 is selected such that it does not collide with the substrate 39 even in the maximum tilted pivoting position of the individual mirror 20.

To measure the capacitance between the transmitter electrode 47 and the receiver electrode 48 of the sensor transducer stator electrodes 44; an electrical voltage, in particular a sensor voltage Us, is applied to the transmitter electrode 47. An alternating voltage in particular serves as the sensor voltage Us.

The sensor device 41 is particularly sensitive with regard to the immersion depth of the comb fingers 46 between adjacent comb fingers of the sensor transducer stator electrodes 44; ( 6 ).

The sensor device 41 is particularly insensitive to a mere pivoting of the comb finger 46 relative to the transmitter electrode 47 and the receiver electrode 48 ( 7 ).

The sensor device 41 is particularly insensitive to a lateral displacement of the shielding element, which changes the distance between it and the transmitter electrode 47 and the receiver electrode 48, the immersion depth of the comb finger 46 between the adjacent transmitter and receiver electrodes 47, 48, however, remains unchanged.

Further details of the sensor device are described in more detail below.

The sensor transducer stator electrodes 44i are preferably within the ring of the actuator transducer stator electrodes 37; arranged. In this area, the absolute movements of the comb fingers 46 in the direction parallel to the surface normal 36 are smaller than outside the ring of the actuator-transducer-stator electrodes 37i. The absolute range of movement depends on the distance to the effective pivot point 37.

In the embodiments shown in the figures, the sensor transducer stator electrodes 44; radially inwardly across the inner envelope of the actuator transducer stator electrodes 37; out. It is also possible to use the sensor transducer stator electrodes 44; to be designed in such a way that they do not extend beyond the inner envelope of the actuator-transducer stator electrodes 37; stand out.

The sensor transducer stator electrodes 44i are formed and arranged radially relative to the effective pivot point 35. In particular, they have comb fingers that run in the radial direction. This reduces the sensitivity with regard to possible thermal expansion of the individual mirror 20.

As was already explained above, the sensor device 41 has, due to its design, at most a minimal sensitivity with regard to parasitic movements of the individual mirror 20, in particular with regard to displacements perpendicular to the surface normal 36 and/or rotations about the surface normal 36. Due to the shielding principle of the sensor device 41, it also has at most a minimal sensitivity with regard to possible thermal expansion of the individual mirror 20. Furthermore, the sensor principle has minimal sensitivity with regard to thermal bending of the mirror.

Two sensor units opposite each other with respect to the effective pivot point 35, each with a transmitter electrode 47 and a receiver electrode 48, are differentially connected or at least differentially readable. This makes it possible to eliminate interference in the measurement of the position of the mirror 20, in particular due to natural modes of the individual mirror 20.

The active components of the sensor device 41 are arranged on the substrate 39. This makes it possible to measure the tilt angle of the individual mirror 20 directly relative to the substrate 39. In addition, due to the arrangement of the transmitter electrodes 47 and the receiver electrodes 48 on the substrate 39, the length of the signal line and/or the supply lines can be reduced, in particular minimized. This reduces possible interference. This ensures constant operating conditions.

The transmitter electrodes 47 can each be designed as an active shield, in particular as a shielding ring around the receiver electrodes 48. This causes capacitive crosstalk between the actuator-transducer-stator electrodes 37; and the sensor device 41 reduced, in particular minimized, in particular prevented.

The joint 32 is designed in particular as a gimbal solid-body joint.

According to a variant, the joint 32 is designed as a torsion spring element structure. In particular, it can include two torsion springs 50, 51. The two torsion springs 50, 51 are made in one piece. In particular, they are aligned perpendicular to one another and form a cross-shaped structure 49.

One torsion spring 50 extends in the direction of the tilt axis 33. The torsion spring 50 is mechanically connected to the substrate 39. Connecting blocks 52 are used to connect the torsion spring 50 to the substrate 39. The connecting blocks 52 are each cuboid-shaped. They can also be cylindrical, in particular circular cylindrical. Other geometric shapes are also possible.

The connecting blocks 52 are each arranged in an end region of the torsion spring 50.

In addition to connecting the joint 32 to the substrate 39, the connecting blocks 52 also serve as spacers between the torsion spring 50 and the substrate 39.

Corresponding to the connection of the torsion spring 50 to the substrate 39, the torsion spring 51 is mechanically connected to the mirror body 27 of the individual mirror 20. Connection blocks 53 are provided for this purpose. The connecting blocks 53 correspond in their design to the connecting blocks 52. The connecting blocks 53 are each arranged in an end region of the torsion spring 51.

The connection blocks 53 and the connection blocks 52 are arranged on opposite sides of the cross-shaped structure 49 in the direction of the surface normal 36.

The torsion springs 50, 51 of the joint 32 have a T-shaped profile in the region of the legs of the cross-shaped structure 49 adjoining the central region. The torsion springs 50, 51 are thereby stiffened, in particular with regard to deflections in the direction of the surface normal 36. This ensures that the natural frequency of the mirror 20 is shifted in the vertical direction towards high frequencies and thus a mode separation of the regulated tilting modes and the parasitic vertical oscillation mode more than a decade in the frequency domain, which is advantageous in terms of control technology. In addition, the thermal conductivity of the joint 32 can be increased by the cross-shaped stiffening element.

In principle, it is possible to also arrange a corresponding stiffening element on the opposite side of the cross-shaped structure 49. In this case, the legs of the torsion springs 50, 51 have a cross-shaped cross section.

The joint 32 is stiff with regard to rotations about the surface normal 36. The joint 32 is stiff with regard to linear displacement in the direction of the surface normal 36. In this context, stiff means that the natural frequency of the rotational vibrations about the surface normal 36 or the natural frequency of the vibrations in the direction of the surface normal lies by more than one frequency decade above the actuated modes. The actuated tilting modes of the individual mirror are in particular at frequencies below 1 kHz, in particular below 600 Hz. The natural frequency of the rotational oscillations around the surface normal 36 is more than 10 kHz, in particular more than 30 kHz.

The joint 32 has a known flexibility with regard to pivoting about the two tilting axes 33, 34. The rigidity of the joint 32 with regard to pivoting about the tilting axes 33, 34 can be influenced by a targeted design of the torsion springs 50, 51.

The joint 32, in particular the connecting blocks 52, 53 and the torsion springs 50, 51 serve to dissipate heat from the mirror body 27. The components of the joint 32 form heat conduction sections.

The joint 32 including the connecting blocks 52, 53 has several functions. Firstly: binding of the non-actuated degrees of freedom, secondly, heat transport from mirror 20 to base plate 39 and thirdly, the electrical connection of mirror 20 to base plate 39. The purpose of blocks 52, 53 is primarily to create space for the vertical movement of the joint element. Of course, the blocks 52, 53 must then also pass on the mechanical, thermal and electrical functions of the springs 50, 51.

The torsion springs 50, 51 are made of a material with a thermal conductivity coefficient of at least 50 W/(mK), in particular at least 100 W/(mK), in particular at least 140 W/(mK).

The torsion springs 50, 51 can be made of silicon or a silicon compound. The joint 32 is preferably made of highly doped monocrystalline silicon. This opens up process compatibility of the manufacturing process with established MEMS manufacturing processes. This also leads to an advantageously high thermal conductivity and good electrical conductivity.

With an absorbed power density in the range from 5 kW/(m ² ) to 20 kW/m ² , for example 10 kW/m ² , and a mirror size of 600 µm x 600 µm, the specified values of the dimensions, in particular with a thickness, result the torsion springs 50, 51 of 4 µm, and the thermal conductivity of the torsion springs 50, 51 a temperature difference between the mirror body 27 and the substrate 39 of approximately 11 K.

The torsion springs 50, 51 can also have a smaller thickness. With a thickness of the torsion springs 50, 51 of 2.4 μm, there is a temperature difference between the mirror body 27 and the substrate 39 of 37 K - with otherwise identical parameter values.

In a variant of the joint 32, two pairs of spiral springs are provided instead of the torsion springs 50, 51. With this alternative, too, the joint 32 has a high degree of rigidity in the horizontal degrees of freedom. In this regard, reference is made to the previous description.

The design aspects with regard to the horizontal stiffness and with regard to the mode separation of the parasitic eigenmodes also correspond to those described previously.

A variant of the joint 32 is a cardanic solid-state joint with orthogonally arranged, horizontal bending springs designed as leaf springs. Two of the spiral springs are connected to each other by means of a plate-shaped structure, which is also referred to as an intermediate plate.

Horizontal leaf springs are advantageous in terms of process technology. They particularly facilitate the production of the joint 32.

In this variant, the connecting blocks 52, 53 can each be elongated, rod-shaped. They can extend essentially over the entire extent of the joint 32 in the direction of the tilt axes 33, 34.

A separating slot can be provided between two of the connecting blocks 52, 53. The joint 32 is therefore designed in two parts.

The joint 32 is preferably designed axially symmetrical to the surface normal 36. It therefore has two-fold rotational symmetry. In particular, the spiral springs can each be mirrored be designed symmetrically to the surface normal 36.

In one case, the stiffening element 55 is designed in the form of two plate-shaped structures. The plate-shaped structures can in particular be arranged parallel to the plane defined by the pivot axes 33, 34. The plate-shaped structures connect the pivot axes 33, 34 realized by the bending springs. The pivot axes 33, 34 are in particular aligned orthogonally to one another.

Further details of the individual mirrors 20, in particular their displacement device 31 (actuator device) and the sensor device 41, are described below.

The details described below can also be implemented in the previously described embodiments and/or combined with details of the same. With regard to details not described in detail below, reference is made in particular to the previous description.

The individual mirrors 20 and the mirror array 19 are in particular a micromirror array. In particular, it is a microelectromechanical system (MEMS).

The individual mirrors 20, especially the mirror array 19, can form a component of the field facet mirror 13 or the pupil facet mirror 14.

The field facet mirror 13 and/or the pupil facet mirror 14 can each have a plurality of such mirror arrays 19. In particular, you can have several hundred such mirror arrays.

The reflection surface 26 of the individual mirrors 20 can be square as described above. It can also have a shape that is closer to a circular shape. The reflection surface 26 can in particular be hexagonal, in particular as a regular hexagon. This allows direction-dependent differences in the tilting of the individual mirrors 20 to be reduced. In addition, the circumference to area ratio can be reduced. This can lead to an increased filling factor. Overall, the mechatronic behavior of the individual mirrors 20 can thereby be improved.

The individual mirrors 20 can have a displacement accuracy of at least 50 µrad.

Like in the 4 is shown as an example, the comb fingers of the displacement device 31 and/or the sensor device 41 can each be arranged in an annular region 61, 62.

The annular regions 61, 62 can be arranged concentrically to one another, in particular concentrically to the surface normal 36.

Like especially in the 5 until 7 is shown as an example, the reflection surface 26 can be hexagonal. This leads to an approximately 15% reduction in the distance between the center (effective pivot point 35) of the individual mirror 20 and the farthest corner of the individual mirror 20 compared to a square design of the reflection surface 26 of the same area. A smaller distance leads to a smaller lateral displacement of the individual mirror 20 when pivoting. This in turn means that the distance between adjacent individual mirrors 20 can be reduced, which results in a higher fill factor and thus higher transmission.

A hexagonal individual mirror 20 also leads to a circumference reduced by approximately 5% compared to a square individual mirror 20 of the same area. This also leads to a higher fill factor and thus to higher transmission.

In addition, with a hexagonal individual mirror 20, the heights of the comb fingers 38, 43 can be reduced. Due to the smaller distance from the pivot point 35 to the corners of the individual mirror 20, there is a reduced vertical displacement of the individual mirror 20 during pivoting.

With a hexagonal mirror, the corners can be better covered with radial comb structures. This leads to improved use of the area behind the individual mirror 20 for the actuator system. As a result, a higher force or a higher torque can be generated with the same area.

Due to an increased remaining gap between the longest comb fingers, direction-dependent parasitic movements can be reduced.

The gap between comb fingers can be reduced. In other words, this means that the number of comb fingers per unit area can be increased. This can also increase the force/torque that can be generated. This causes the joint 32 can be made stiffer. This enables better thermal conductivity of the joint 32.

In the case of a three-fold rotational symmetry of the displacement device 31, the area of the front-end actuator drivers can be increased compared to that for a four-fold symmetry. This allows the force and torque to be increased, in particular by a factor of almost 2.

The hexagonal x-y asymmetry fits well with the elliptical displacement region.

Like in the 5 is shown as an example, the displacement device 31 can have a threefold rotational symmetry with 3 actuator areas A1, A2, A3.

The sensor device 41 can have four-fold rotational symmetry with four sensor areas S1, S2, S3, S4.

In general, the displacement device 31 and the sensor device 41 can have different, in particular different, rotational symmetries.

The symmetry properties of the displacement device 31 can be adapted in particular to the symmetry properties of the reflection surface 26. The rotational symmetries of the reflection surface 26 and the displacement device 31 can in particular be an integer multiple of one another.

The sensor device 41 can in particular have a rotational symmetry which is adapted to the rotational symmetry properties of the object field 5. The sensor device 41 can in particular have a two-fold or a four-fold rotational symmetry.

The sensor device 41 can in particular have a rotational symmetry, the number of which is adapted to the joint 32, in particular an integer multiple of the number of the rotational symmetry of the joint 32.

The sensor device 41 and the joint 32 can in particular have rotational symmetries with identical numbers.

In the in 6 In the variant shown schematically, the displacement device 31 has four-fold rotational symmetry. The displacement device 31 has in particular four actuator areas A1 to A4.

The sensor device 41 has four-fold rotational symmetry. The reflection surface 26 has six-fold rotational symmetry.

At the in the 7 In the variant shown schematically, the displacement device 31, like the reflection surface 26, has a six-fold rotational symmetry. The displacement device 31 has in particular six actuator areas A1 to A6.

The sensor device 41 has four-fold rotational symmetry. The joint 32 has the same as in the variants according to 5 and 6 a twofold radial symmetry.

It could be shown that a pivoting of the individual mirror 20 with a hexagonal reflection surface 26 corresponds to one of those in the 5 until 7 shown variants by 120 mrad with the same size of the reflection surface 26 leads to a reduced vertical displacement of the mirror body 27 by approximately 10 μm compared to a single mirror 20 with a square reflection surface 26 of the same area of 1 mm ² .

This means that the distance between the mirror body 27 and the substrate 39 can be reduced. The mirror body 27 can thus be arranged closer to the center of the pivoting. This leads to a reduction in the parasitic deflection of the mirror body 27 during pivoting. A reduction in the parasitic deflection of the mirror body 27 can in turn be exploited in such a way that the distance between adjacent mirrors and/or the distance between adjacent actuator fingers can be reduced. The latter allows the force and torque that can be generated to be increased. This in turn allows the use of stiffer springs for the joint 32, resulting in improved thermal conductivity.

Furthermore, it could be shown that the remaining gap between adjacent comb fingers at a maximum pivoting of the individual mirror 20 in the case of hexagonal reflection surfaces 26 is over 10% larger than in the case of square reflection surfaces 26 (reflection surface: 1 mm ² ; pivoting 120 mrad).

With a hexagonal reflection surface 26, the height of the comb fingers can be reduced by approximately 10%. Due to the reduced vertical displacement of the comb fingers relative to the pivot point 35, there is also a smaller lateral displacement of the mirror body 27, in particular its corners and edges. Therefore he can Distance between adjacent reflection surfaces 26 can be reduced and thus the fill factor and the transmission can be increased.

It was also shown that the distance between adjacent reflection surfaces 26 or mirror bodies 27 could be reduced by approximately 7% compared to square mirrors when they were designed hexagonally. The fill factor could be increased by more than 1%.

Like in the 8th is shown schematically, a plurality of individual mirrors 20 with hexagonal reflection surfaces 26 can be combined to form a mirror module 65. The mirror module 65 may have a jagged edge 66. The edge 66 of the mirror module 65 can follow the treatment of the outer individual mirrors 20 in sections.

The individual mirrors 20 are preferably arranged in the illumination optics 4 in such a way that their boundary edges enclose an angle of at least 10°, in particular at least 20°, in particular at least 30° with the scanning direction when the individual mirrors 20 are imaged into the object field 5. In particular, they can be arranged in such a way that the image of their boundary edges includes the following angles with the scanning direction: (90°, 30°, -30°).

Like in the 9 is shown as an example, the mirror module 65 can also have a smooth edge 66. This makes it easier to produce the mirror arrays 19. The mirror modules 65 can in particular be sawed out very easily from larger arrays.

As exemplified in the 10 and 11 is shown, the mirror modules 65 can also be essentially square, in particular rectangular or parallelogram-shaped (non-rectangular). In this case you can also use a jagged edge 66 (see 10 ) or a smooth edge 66 (see 11 ) exhibit.

Like in the 12 is shown as an example, several mirror modules 65 can be placed together essentially without gaps.

The mirror modules 65 themselves preferably each have a shape which enables tiling, in particular monohedral tiling, of the plane.

Mirror modules 65 with smooth edges 66 lead to a particularly simple arrangement of the mirror modules 65 relative to one another.

Mirror modules 65 with a jagged edge 66 enable a larger fill factor.

Like in the 13 shown as an example, a mirror module 65 can comprise 331 hexagonal individual mirrors 20. The individual mirrors 20 can be arranged in 11 rings. The arrangement of the individual mirrors 20 and their mutual spacing can be continued beyond the edges of the individual mirror modules 65 with a suitable arrangement of the mirror modules 65. Here, a gap of a width of one individual mirror 20 can remain between adjacent mirror modules 65.

Like in the 14 is shown as an example, the losses due to abutting mirror modules 65 can be further reduced if the edges 66 are jagged. This allows for a higher fill factor.

For example, a laser cutting process can be used to cut mirror modules 65 with a jagged edge 66.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015204874 A1 [0002]
• WO 2010049076 A [0058]
• WO 2016146541 A1 [0058]
• EP 1225481 A2 [0062]
• WO 2012130768 A2 [0071]
• DE 102013206529 A1 [0077]

Claims (15)

Individual mirror (20) of a facet mirror (13, 14) of an illumination optics (4) of a projection exposure system (1) 1.1. with a reflection surface (26) with a surface normal (36), 1.2. with a bearing which enables the surface normal (36) of the individual mirror (20) to be pivoted, 1.3. with an actuator device (31) for pivoting the individual mirror (20) and 1.4. with a sensor device (41) for detecting the pivoting position of the individual mirror (20), 1.5. characterized in that 1.5.1. the sensor device (41) and the actuator device (31) have rotational symmetries with different counts and/or 1.5.2. the sensor device (41) and the reflection surface (26) or a substrate on which the reflection surface is formed have rotational symmetries with different counts. Individual mirror (20) according to Claim 1 , characterized in that the reflection surface (26) is hexagonal. Individual mirror (20) according to one of the preceding claims, characterized in that the actuator device (31) has a 3-fold or a 6-fold rotational symmetry. Individual mirror (20) according to one of the preceding claims, characterized in that the sensor device (41) has a 2-fold or a 4-fold rotational symmetry. Individual mirror (20) according to one of the preceding claims, characterized in that the bearing has a cardan joint (32) with two pivot axes (33, 34) running transversely to the surface normal. Individual mirror (20) according to one of the preceding claims, characterized in that the actuator device (31) and/or the sensor device (41) have a plurality of comb electrodes which extend radially to the surface normal of the reflection surface (26) of the individual mirror (20). Has comb fingers. Facet module () for a facet mirror (13, 14) of an illumination optics (4) of a projection exposure system (1). 7.1. a plurality of individual mirrors (20) according to one of the preceding claims 7.2. wherein the individual mirrors (20) are arranged in the manner of a regular tiling. Facet module according to Claim 7 , characterized in that it is designed such that it forms a tile for monohedral regular tiling of a level. Facet module according to one of the Claims 7 until 8th , characterized in that it has a fill factor of at least 91% with a pivoting range of the individual mirrors of at least 120 mrad around each of the pivot axes (33, 34). Field facet mirror (13) for an illumination optics (4) of a projection exposure system (1) with a plurality of individual mirrors (20) according to one of Claims 1 until 6 and/or a plurality of facet modules according to one of Claims 7 until 9 . Illumination optics (4) for a projection exposure system (1) with 11.1. a field facet mirror (13). Claim 1 and 6 11.2. a pupil facet mirror (14), by means of which field facets can be imaged into an object field (5). Illumination optics (4) according to Claim 11 , characterized in that the facet modules of the field facet mirror (13) are arranged in such a way that the edge contours of the individual mirrors (20) enclose an angle with a scanning direction of at least 10° when imaging into the object field (4). Lighting system (2) for a projection exposure system (1) comprising 13.1. a lighting optics (4) according to one of Claims 11 until 12 and 13.2. a radiation source (3) for generating illumination radiation (10). Projection exposure system (1) for microlithography comprising 14.1. a lighting optics (4) according to one of Claims 11 until 12 , 14.2. a radiation source (3) for generating illumination radiation (10) and 14.3. a projection optics (7) for imaging a reticle arranged in the object field (5) into an image field (8). Method for producing a micro- or nanostructured component comprising the following steps: 15.1. Providing a projection exposure system (1) according to Claim 14 , 15.2. Arranging a reticle with structures to be imaged in the object field (5), 15.3. Imaging the reticle onto a radiation sensitive locative layer of a wafer arranged in the image field (8).

Images