DE102015220018A1 - Method for producing a microelectromechanical component with at least one movable component - Google Patents

Abstract

In a method for producing a MEMS component (30) with at least one movable component, separate joining parts (71, 72) are produced and precisely assembled in a joining step.

Description

The invention relates to a method for producing a microelectromechanical component having at least one movable component, in particular a micromirror, in particular a displaceable micromirror for a micromirror array of a projection exposure apparatus, in particular an EUV projection exposure apparatus. The invention further relates to a micromirror, a micromirror array with such a micromirror, an optical system having such a micromirror array and a projection exposure apparatus with such an optical system. Finally, the invention relates to a method for producing a micro- or nanostructured component as well as a device manufactured according to the method.

A projection exposure apparatus with a micromirror array is known, for example, from US Pat WO 2012/130768 A2 and the DE 10 2013 204 546 A1 known.

There is a continuing need to improve such a micromirror array and its components and a method of making the same.

This object is achieved inter alia by a method according to claim 1.

The essence of the invention is to produce a microelectromechanical component of two or more parts to be joined together in a joining step with high precision. The microelectromechanical component is thus composed of initially separate components. Surprisingly, it has been found that this makes it possible to simplify the production of the microelectromechanical component. The movable component is triggered in particular after the joining of the joining parts, in particular etched free. He is in particular at least until joining the joining parts with one of these fixed.

Although a high accuracy is necessary for the assembly of the individual components, however, the required precision can be achieved, in particular with the aid of adjustment and / or alignment structures on the parts to be joined.

The parts to be joined in particular with an accuracy of better than 5 .mu.m, in particular better than 3 .mu.m, in particular better than 2 .mu.m, in particular better than 1 micron assembled. The accuracy relates in particular to at least one spatial direction, in particular a direction perpendicular to a surface normal of the substrate for producing the first joining part. The accuracy relates in particular to two mutually perpendicular spatial directions perpendicular to the surface normal. The accuracy may also refer to the direction of the surface normals. It preferably refers to all three spatial directions.

In principle, the accuracy with which the joining parts are joined together can be different in different spatial directions. It may be better in particular in the direction perpendicular to the surface normal than in the direction parallel thereto.

The accuracy relates in particular to the arrangement of the movable component or components of the optical component relative to the immovable, fixed components. Due to the high accuracy, it can be ensured that the movable component or components can fully exploit their intended range of motion without colliding with other components of the optical component. In particular, a minimum distance in one or more predetermined spatial directions to all other components of the optical component can be ensured.

The at least one movable component has in particular over its entire range of motion a predetermined minimum distance to all other components of the optical component. The minimum distance may in particular be in the range of 0.1 μm to 10 μm, in particular in the range of less than 5 μm, in particular less than 3 μm, in particular less than 2 μm, in particular less than 1 μm.

The microelectromechanical component (MEMS component) is in particular a micromirror, in particular a displaceable micromirror, in particular a micromirror for a micromirror array, that is to say a multi-mirror arrangement, in particular for a projection exposure apparatus for microlithography, in particular for EUV lithography.

The functional structures may be any structures with a MEMS function. These are in particular actuators, in particular with electrodes, in particular with comb electrodes, sensors, in particular with electrodes, in particular with comb electrodes, bending structures, joint structures, in particular solid-body joint structures, in particular gimbal joint structures or the like. Details will become apparent from the description of the embodiments.

The functional structures are, in particular, structures that are displaceable and / or deformable in the finished state of the microelectromechanical component.

According to one aspect of the invention, the functional structures of the two joining parts after the joining of the joining parts on an overlap z in the direction parallel to the central surface normal of the first substrate. The overlap z is in particular at least 5 μm, in particular at least 10 μm, in particular at least 20 μm, in particular at least 30 μm, in particular at least 40 μm, in particular at least 50 μm. The overlap can hereby be measured in an untwisted neutral position of the microelectromechanical component, in particular of the micromirror. It is also possible for the indication of the overlap to refer to the maximum pivoted position of the microelectromechanical component, in particular of the micromirror. It can relate in particular to the entire extent of displacement of the component.

Due to the high precision in joining the joining parts, this has been found to be possible.

In particular, the functional structures of the two joining parts have a minimum distance in the direction perpendicular to the surface normal of the first substrate of at least 1 μm, in particular at least 2 μm, in particular at least 3 μm, in particular at least 5 μm. The minimum distance can be measured here in an untwisted neutral position of the microelectromechanical component, in particular of the micromirror. It is also possible that the indication of the minimum distance relates to the maximum pivoted position of the microelectromechanical component, in particular of the micromirror. It can relate in particular to the entire extent of displacement of the component.

In particular, in the latter case it is ensured that the two joining parts do not collide with each other in a pivoting relative to each other in the intended pivoting range.

According to a further aspect of the invention, it is provided that at least a part of the first functional structures interact with at least one part of the second functional structures after joining the joining parts or form common functional structures.

The functional structures of the finished microelectromechanical component can be composed in other words. In particular, they can be composed of components of different parts to be joined. You can hereby be formed one or more parts.

The functional structures of the first and second joining parts can form an electrode-counterelectrode pair, in particular after joining the joining parts. In this case, they act together as a common electrode structure.

According to a further aspect of the invention, all the joining parts are assembled in such a way that their functional structures are inaccessible after assembly.

Here comes the idea to make separate parts with functional structures and put together only after the production of the joining parts, especially good to wear.

In particular, the functional structures form a relief structure which projects in the direction of the surface normal from the respective substrate. In other words, the parts to be joined form parts, in particular half parts, which are bounded in the direction of the surface normal of the respective substrate by the planar substrate structure, in particular closed, but open to the opposite direction, in particular into the opposite half space. Details result in particular from the description of the embodiments with reference to the figures.

In accordance with a further aspect of the invention, vertical structuring steps are respectively provided for producing at least one, in particular both joining parts from the substrates. In particular, only vertical structuring steps are provided.

Deposition cuts for the deposition of material for the production of the functional structures can be completely dispensed with. Of course, masking can be applied to the vertical patterning cuts. These will be removed afterwards.

The structuring steps are in particular exclusively triggering steps, in particular etching steps, for example isotropic or anisotropic etching or deep etching, in particular so-called reactive ion etching (DRIE, deep reactive ion etching, deep reactive ion etching). In particular, the functional structures are prepared from the substrates, in particular cut out and / or etched out. In contrast to other manufacturing processes, it is possible, but not absolutely necessary, to dispense completely with deposition processes, apart from masking steps. It can be applied in particular to deposition processes for the deposition of Material from which the functional structures are produced, are dispensed with. This leads to a considerable time savings. This also leads to a better controllability, in particular a better precision in the production of the parts to be joined.

According to a further aspect of the invention, the functional structures are formed real three-dimensional. By this is meant in particular that the functional structures in the direction perpendicular to a surface of the substrate from which they are made have an extension which at least 5%, in particular at least 10%, in particular at least 20%, in particular at least 30%, in particular at least 40%, in particular at least 50% of the extent of the MEMS component, in particular of the micromirror, in this direction. The extent of the functional structures in the direction parallel to the surface normal of the substrate is in particular at least 10 μm, in particular at least 20 μm, in particular at least 50 μm, in particular at least 100 μm, in particular at least 200 μm. The functional structures are arranged in particular obliquely, in particular perpendicular to a functional plane. As a result, they differ significantly from functional structures which are produced by a sequence of deposition or application and structuring steps.

According to a further aspect of the invention, the first functional structures comprise comb fingers of a first comb electrode and the second functional structures comb fingers of a second comb electrode, the second functional structures comb fingers of a second comb electrode, wherein the second comb electrode forms a counter electrode to the first comb electrode after joining the joining parts ,

A particularly advantageous application of the method is to be seen in a production of a displaceable micromirror, wherein comb electrodes are provided for displacing the micromirror. The comb electrodes can also form a sensor device, in particular for detecting the displacement position of the micromirror.

According to a further aspect of the invention, the first functional structures form, together with the second functional structures, a bending structure, in particular a joint structure, in particular a solid-state joint, in particular a cardanic solid-state joint, after the joining parts have been assembled. The functional structures of the two joining parts can in particular be joined together, in particular bonded, to form such a structure.

According to a further aspect of the invention, the different joining parts are produced in parallel processes.

The production of the different joining parts is thus independent of each other. It is especially possible at the same time.

This too leads to an improvement of the method, in particular to a time saving. According to a further aspect of the invention, the joining parts are subjected to a testing process before assembly.

This reduces the rejects. In particular, it is possible to check the parts to be joined, in particular their functional structures, prior to assembly for proper functionality. The joining parts can be checked in particular at a time at which the functional structures are still freely accessible.

According to a further aspect of the invention, further process steps, in particular for the finalization, ie completion, of the microelectromechanical component are provided after joining the joining parts. In particular, it may be provided to form optical and / or electrical and / or mechanical interfaces on the MEMS component. The MEMS component can in particular be provided with electrical and / or mechanical connections or inclusions. Also a MEMS functionalization or activation is possible. For example, a coating, in particular an optical coating, in particular a reflective coating, in particular an EUV-reflective coating, can be applied to one of the substrates. In addition, it is provided to trigger the moving parts of the MEMS component, in particular of the micromirror, after the joining of the parts to be joined, that is to say to produce the displaceability. Advantageously, the moving parts in the finished component until the joining of the parts to be joined to the respective substrate mechanically, in particular cohesively, in particular in one piece, connected. This serves to protect the movable components, in particular during the joining step.

The objects according to the invention are also achieved by a micromirror, in particular a displaceable micromirror, in particular for a micromirror array, in particular a projection exposure apparatus, in particular an EUV projection exposure apparatus.

In the micromirror, at least the functional structures are at least partially made of monocrystalline silicon. Regarding the definition of what is meant by functional structures refer to the previous description. The functional structures are in particular at least 50% monocrystalline silicon. Advantageously, at least part of the functional structures, in particular all functional structures, are completely made of monocrystalline silicon. This applies in particular to flexural structures, in particular joint structure of the micromirror, in particular the solid-body joint, in particular the gimbal joint for suspending the micromirror and / or its actuator and / or sensor device. In particular, the comb electrodes may be made of monocrystalline silicon. In particular, they can be made entirely from monocrystalline silicon.

The functional structures have in particular an overlap and / or a minimum distance according to the previous description.

According to one aspect of the invention, the mirror body is made of monocrystalline silicon. In particular, apart from a subsequently applied coating, in particular a radiation-reflecting coating, in particular an EUV-reflecting coating, it can consist of monocrystalline silicon.

In particular, the micromirror has a reflection surface with a polygonal or a round shape. The reflection surface can in particular be triangular, quadrangular, in particular square, or hexagonal. In particular, it has an edge length or a diameter in the range of 10 μm to 10 mm, in particular in the range of 100 μm to 1 mm. Other dimensions are also possible.

In particular, the micromirror has an EUV-reflective coating.

As previously described, the functional structures of the micromirror are by relief molding from the monolithic starting substrate.

Due to the monocrystalline structure, the functional structures have particularly advantageous properties. The production of the functional structures from monocrystalline silicon leads in particular to an improved thermal conductivity of the same. It also leads to improved mechanical and / or electrical properties. In addition, the precision in the production of the functional structures is improved and facilitates the production thereof. Another advantage is that the functional structures can be produced in a very reproducible manner, and indeed with a narrow tolerance range with respect to their properties.

According to one aspect of the invention, the functional structures have an extension in the direction parallel to a central surface normal of the micromirror, which is at least 5%, in particular at least 10%, in particular at least 20%, in particular at least 30%, in particular at least 40%, in particular at least 50 % of an extension of the mirror body in the direction perpendicular thereto.

In comparison to conventionally produced micromirrors, the functional structures of the micromirror can have a very high aspect ratio.

The extent of the mirror body in the direction perpendicular to the surface normal may be an edge length of the mirror body. It may also be the maximum extent of the mirror body in the direction perpendicular to the surface normal.

By such a large aspect ratio, the electrical and / or mechanical properties of the functional structures can be improved. In particular, it is possible to improve the transmission of force between the electrodes and the associated counterelectrodes. In particular, the micromirror has an enclosed, in particular, an encapsulated arrangement, functional mechanical and / or electrical structures. These are thus protected against external influences. The large vertical extent of the functional structures allows a larger amount of displacement, in particular a larger maximum tilt angle. It also leads to an improved sensor signal, in particular a higher achievable sensitivity.

According to a further aspect of the invention, the mirror body is displaceable relative to the support structure, wherein the functional structures of the first joining part and the functional structures of the second joining part over the entire range of motion of the mirror body have a predetermined minimum distance from each other.

The micromirror, in particular its functional structures, in particular the one or more displaceable components of the micromirror, are of very precise design and / or arranged relative to one another. To achieve the high precision, the known and advantageous properties of monocrystalline silicon prove to be particularly useful and advantageous.

The object according to the invention is also achieved by a micromirror micromirror array according to the preceding description.

The advantages result from the previously described.

The number of micromirrors in the micromirror array may be at least 4, in particular at least 16, in particular at least 64, in particular at least 250, in particular at least 1000.

The micromirrors have a high integration density. The integration density (filling factor) of the micromirror 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 object according to the invention is also achieved by an optical system for a projection exposure apparatus and a projection exposure apparatus having a corresponding optical system with at least one micromirror array according to the preceding description.

The advantages again result from those already described. Another object of the invention is to improve a method of manufacturing a micro- or nanostructured device. This object is achieved by the provision of a projection exposure apparatus according to the invention. The advantages in turn result from the previously described. Finally, the invention relates to a device produced according to the method.

This is characterized by an increased precision.

Further aspects, advantages and details of the invention will become apparent from the description of embodiments with reference to the drawings. 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 counterelectrodes or shielding elements arranged thereon is folded to the side,

4 schematically a plan view of the section IV in 3 with a schematic representation of the electrical connection of a part of the sensor device,

5 a view according to 4 in which the comb fingers connected to the mirror body are not shown,

6 a schematic representation of a further variant of the optical component with a counterweight to place the center of gravity of the moving mirror in the pivot point of the joint,

7A to 7E 1 is a schematic view of a sequence of intermediates and method steps in the production of a first joining part;

8th a view of 7E from underneath

9A to 9K a sequence of intermediates and process steps in the manufacture of a second adherend,

10 a view of the intermediate product according to the 9B from above,

11 a view of the intermediate according to 9K from above,

12A to 12E 3 shows a schematic view of the intermediates and method steps in the production of the microelectromechanical component from the two parts to be joined, in particular the step of assembling the two parts to be joined ( 12A ) and subsequent processing steps,

13 a view of the intermediate product according to the 12D from underneath,

14A to 14F schematic views of intermediates in the production of the second joining part of an alternative, the views of the 14B and 14C give views of the same intermediate with different orientations,

15A a view of the intermediates according to the 14A to 14C from above (the line XIV A-XIV A hereby indicates the orientation of the representation according to the 14A again; the line XIV B-XIV B hereby indicates the orientation of the representation according to the 14B again; the line XIV C-XIV C hereby indicates the orientation of the representation according to the 14C again),

15B a view of the intermediates according to the 14B and 14C from above,

16A to 16F 1 schematically shows a sequence of intermediates and method steps in the production of the first joining part according to a variant with a balance weight,

17 a view of the intermediate product according to the 16F from below (the line XVI F-XVI F indicates the orientation of the illustration according to the 16F again),

18A to 18K schematically intermediate products and method steps in the production of the second joining part according to a variant with a balance weight,

19 very schematically a view of the intermediate product according to the 18D from above (the line XVIII D-XVIII D gives the orientation of the 18D again),

20 schematically a representation of the intermediate product according to the 18G from above (the line XVIII G-XVIII G again gives the orientation of the representation of the 18G again),

21 a schematic view of the intermediates according to the 18I and 18J from above (the line XVIII I-XVIII I here gives the orientation of the representation of 18I again; the line XVIII J-XVIII J gives the orientation of the representation of the 18J again),

22 a schematic representation of the intermediate according to the 18K from above (the line XVIII K-XVIII K gives the orientation of the representation of the 18K again),

23A to 23H a schematic representation of a sequence of intermediates and process steps in the production of the microelectromechanical component of the two parts to be joined according to a further variant with a balance weight, here are 23C a schematic representation along the line XXIII-XXIII in 24 again,

24 a representation of the intermediate according to the 23C from underneath,

25 a schematic view of the device according to the 23H along the line XXV-XXV, and

26 a schematic representation of 23H along the line XXVI-XXVI.

The figures shown are merely intended to illustrate the invention, in particular the successive process steps. The sectional views are in particular not only simple sectional views along a single cutting plane, but also schematic representations with selected details. In the views from above or from below, individual layers and / or elements are sometimes removed or hidden elements are shown. For reasons of clarity, corresponding elements have not been represented with their own line type.

First, the general structure of a projection exposure apparatus 1 and their components are described. For details in this regard is on the WO 2010/049076 A2 which is hereby incorporated in its entirety as part of the present application. The description of the general structure of the projection exposure apparatus 1 is to be understood only as an example. It serves to explain a possible application of the subject 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 apparatuses.

1 schematically shows in a meridional section a projection exposure system 1 for microlithography. A lighting system 2 the projection exposure system 1 has next to a radiation source 3 an illumination optics 4 for the exposure of an object field 5 in an object plane 6 , The object field 5 may be rectangular or arcuate with an x / y aspect ratio of, for example, 13/1. One is exposed in the object field 5 arranged and in the 1 not shown reflective reticle, the one with the projection exposure system 1 contributes to the production of microstructured or nanostructured semiconductor devices to be projected structure. A projection optics 7 serves to represent the object field 5 in a picture field 8th in an image plane 9 , The structure on the reticle is imaged onto a photosensitive layer in the area of the image field 8th in the picture plane 9 arranged wafer, 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 in operation of the projection exposure apparatus 1 scanned synchronously in the y-direction. Depending on the imaging scale of the projection optics 7 can also take place an opposite scanning of the reticle relative to the wafer.

At the radiation source 3 it is an EUV radiation source with an emitted useful radiation in the range between 5 nm and 30 nm. It can be a plasma source, for example a GDPP source (plasma generation by gas discharge, gas discharge produced plasma), or an LPP Source (plasma generation by laser, laser produced plasma). Other EUV sources, such as those on a synchrotron or on a Free Electron Lasers (FEL) based are possible.

EUV radiation 10 coming from the radiation source 3 emanating from a collector 11 bundled. A corresponding collector is for example from the EP 1 225 481 A2 known. After the collector 11 propagates the EUV radiation 10 through an intermediate focus level 12 before moving to a field facet mirror 13 meets. The field facet mirror 13 is in a plane of illumination optics 4 arranged to the object level 6 is optically conjugated. The field facet mirror 13 can be spaced to one to the object plane 6 be arranged conjugate level. It is generally referred to as the first facet mirror in this case.

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

After the field facet mirror 13 becomes the EUV radiation 10 from a pupil facet mirror 14 reflected. The pupil facet mirror 14 lies either in the entrance pupil plane of the projection optics 7 or in a plane optically conjugated 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 variety of individual mirrors, which are described in more detail below. In this case, the subdivision of the field facet mirror 13 be in individual mirrors such that each of the field facets, which for themselves the entire object field 5 Illuminate, represented by exactly one of the individual mirrors. Alternatively, it is possible to construct at least some or all of the field facets through a plurality of such individual mirrors. The same applies to the configuration of the pupil facets of the pupil facet mirror respectively assigned to the field facets 14 , which may each be formed by a single individual mirror or by a plurality of such individual mirrors.

The EUV radiation 10 meets the two facet mirrors 13 . 14 at a defined angle of incidence. The two facet mirrors are in particular in the range of normal incidence operation, ie with an angle of incidence which is less than or equal to 25 ° to the mirror normal, with the EUV radiation 10 applied. Also, an application under grazing incidence (grazing incidence) is possible. The pupil facet mirror 14 is in a plane of illumination optics 4 arranged, which is a pupil plane of the projection optics 7 represents or to a pupil plane of the projection optics 7 is optically conjugated. Using the pupil facet mirror 14 and an imaging optical assembly in the form of a transmission optics 15 with in the order of the beam path for the EUV radiation 10 designated mirrors 16 . 17 and 18 become the field facets of the field facet mirror 13 overlapping each other in the object field 5 displayed. The last mirror 18 the transmission optics 15 is a grazing incidence mirror. The transmission optics 15 becomes along with the pupil facet mirror 14 also as a follow-up optics for the transfer of EUV radiation 10 from the field facet mirror 13 towards the object field 5 designated. The illumination light 10 is from the radiation source 3 towards the object field 5 guided over a plurality of illumination channels. Each of these illumination channels is a field facet of the field facet mirror 13 and one of these downstream pupil facets of the pupil facet mirror 14 assigned. The individual mirrors of the field facet mirror 13 and the pupil facet mirror 14 can be tiltable actuator, so that a change of the assignment of the pupil facets to the field facets and correspondingly a changed configuration of the illumination channels can be achieved. This results in different lighting settings, resulting in the distribution of the illumination angle of the illumination light 10 over the object field 5 differ.

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

Different illumination settings can be achieved by tilting the individual mirrors of the field facet mirror 13 and a corresponding change of the assignment of these individual mirrors of the field facet mirror 13 to the individual mirrors of the pupil facet mirror 14 be achieved. Depending on the tilt of the individual mirrors of the field facet mirror 13 The individual mirrors newly assigned to these individual mirrors of the pupil facet mirror 14 so tracked by tilting, that in turn an image of the field facets of the field facet mirror 13 in the object field 5 is guaranteed.

Below are more aspects of the lighting optics 4 described.

The one field facet mirror 13 in the form of a multi-mirror or micromirror array (MMA) forms an example of an optical assembly for guiding the useful radiation 10 , the EUV radiation bundle. The field facet mirror 13 is designed as a microelectromechanical system (MEMS). It has a multitude of matrix-like rows and columns in a mirror array 19 arranged individual mirrors 20 on. The mirror arrays 19 are modular design. They can be arranged on a support structure designed as a base plate. Essentially, any number of the mirror arrays can be used here 19 be arranged side by side. The total reflection area, which is determined by the totality of all mirror arrays 19 , in particular their individual mirrors 20 , is formed, is thus arbitrarily expandable. The mirror arrays 19 are particularly designed so that they allow a substantially seamless tiling a plane. The ratio of the sum of the reflection surfaces 26 the individual mirror 20 to the total area, that of mirror arrays 19 is also referred to as 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 be by means of fixing elements 29 fixed on the base plate. For details, for example, on the WO 2012/130768 A2 directed.

The individual mirrors 20 are designed actuatable tilting, as will be explained below. Overall, the field facet mirror 13 about 100,000 of the individual mirrors 20 on. Depending on the size of the individual mirror 20 can the field facet mirror 13 also a different number of individual mirrors 20 exhibit. 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 10000. It can be up to 100,000, in particular up to 300,000, in particular up to 500,000, in particular up to 1,000,000.

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

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

The entire single-mirror array of the facet mirror 13 For example, has a diameter of 500 mm and is densely packed with the individual mirrors 20 designed. The individual mirrors 20 represent, as far as a field facet is realized by exactly one individual mirror, except for a scaling factor, the shape of the object field 5 , The facet mirror 13 can consist of 500 individual mirrors each representing a field facet 20 be formed with a dimension of about 5 mm in the y-direction and 100 mm in the x-direction. Alternatively to the realization of each field facet by exactly one single mirror 20 Each of the field facets can be divided into groups of smaller individual mirrors 20 be approximated. A field facet with dimensions of 5mm in the y-direction and 100mm in the x-direction may e.g. B. by means of a 1 × 20 array of individual mirrors 20 5 mm × 5 mm to a 10 × 200 array of individual mirrors 20 be constructed with the dimensions 0.5 mm × 0.5 mm.

To change the lighting settings, the tilt angles of the individual mirrors 20 adjusted. In particular, the tilt angles have a displacement range of ± 50 mrad, in particular ± 100 mrad. When adjusting the tilt position of the individual mirrors 20 an accuracy of better than 0.2 mrad, especially better than 0.1 mrad, in particular better than 0,05mrad, in particular 0.02 mrad achieved.

The individual mirrors 20 of the field facet mirror 13 and the pupil facet mirror 14 in the execution of the illumination optics 4 to 1 Apply multilayer coatings to optimize their reflectivity at the wavelength of the useful radiation 10 , The temperature of the multilayer coatings should be 425 K while operating the projection exposure equipment 1 do not exceed. This is achieved by a suitable design of the individual mirrors 20 reached. For details will be on DE 10 2013 206 529 A1 referred to, which is hereby fully integrated into the present application.

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

The the majority of individual mirrors 20 having mirror forms together with the evacuable chamber 21 an optical assembly for guiding a bundle of EUV radiation 10 , Each of the individual mirrors 20 can be a reflection surface 26 having dimensions of 0.1 mm × 0.1 mm, 0.5 mm × 0.5 mm, 0.6 mm × 0.6 mm or even up to 5 mm × 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 single mirror 20 , The mirror body 27 wears the multilayer coating.

With the help of the projection exposure system 1 For example, at least a portion of the reticle is imaged onto a portion of a photosensitive layer on the wafer for lithographic fabrication of a micro- or nanostructured device, particularly a semiconductor device, eg, a microchip. Depending on the version of the projection exposure system 1 As a scanner or as a stepper, the reticle and the wafer are synchronized in the y-direction continuously in scanner operation or stepwise in stepper mode.

Below are more details and aspects of the mirror arrays 19 , in particular of the optical components, which the individual mirrors 20 include described.

First, referring to the 2 to 5 a first variant of an optical component 30 with a single mirror 20 and in particular the relocation facility 31 for displacement, in particular for pivoting the individual mirror 20 , described.

The representation according to 3 corresponds to the according to 2 , where in the 3 the mirror body 27 of the single mirror 20 folded away to the side. This will transform the structures of the relocation facility 31 and the sensor device more visible.

4 shows a sectional view of a section of the section IV of the optical component 30 according to 3 parallel to the actuator level.

The optical component comprises the individual mirror 20 , which is designed in particular as a micromirror. The individual mirror 20 includes the previously described mirror body 27 , on whose front the reflection surface 26 is trained. The reflection surface 26 is formed in particular by a multilayer structure. It is in particular radiation-reflecting for the illumination radiation 10 , in particular for EUV radiation.

According to the variant shown in the figures, the reflection surface 26 square formed, but partially cut shown to show the actuator. It is generally rectangular in shape. It can also be triangular or hexagonal. In particular, it is designed in such a tiling manner that seamless tiling of a plane with the individual mirrors 20 is possible. The individual mirror 20 is by means of a joint described in more detail below 32 stored. In particular, it is mounted such that it has two tilting degrees of freedom. The joint 32 allows in particular the tilting of the individual mirror 20 about two tilting axes 33 . 34 , The tilting axes 33 . 34 are perpendicular to each other. They intersect at a central point of intersection, which serves as an effective pivot point 35 referred to as.

Unless the individual mirror 20 is in an untwisted neutral position, so is the effective pivot point 35 on a surface standard 36 which by a central point, in particular the geometric center of gravity of the reflection surface 26 runs.

Unless otherwise indicated, below is the direction of the surface normal 36 always the same direction in the untilted neutral position of the single mirror 20 Understood.

The following is the relocation facility 31 described in more detail.

The relocation facility 31 includes an electrode structure with actuator-transducer stator electrodes 37 _i and actuator transducer mirror electrodes 42 , According to the in the 2 to 5 illustrated variant, the electrode structure comprises four actuator-stator electrodes 37 ₁ , 37 ₂ , 37 ₃ and 37 ₄ . The number of actuator-transducer stator electrodes 37 _i is generally at least 2. It can be 3, 4 or more.

All actuator transducer electrodes 37 _i , 42 are called comb electrodes with a plurality of comb fingers 38 educated. The respective complementary comb fingers of mirror and stator interlock here. The combs of the individual actuator electrodes 37 _i each include 30 Actuator converter Stator comb finger 38 , which are shortened to be referred to below as Storkkammfinger or merely as a comb finger. A different number is also possible. The number of comb fingers 38 the actuator transducer stator electrodes 37 _In particular, _i is 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 include actuator transducer mirror comb fingers 43 , which in the following shortened are also referred to as a mirror comb finger or merely as a comb finger. The number of mirror comb fingers 43 corresponds to the number of Storkkammfinger. It can also differ by one from the number of Storkkammfinger.

The comb fingers 38 are arranged such that they are relative to the surface normal 36 or the effective pivot point 35 in the radial direction. According to a variant, not shown in the figures, the comb fingers 38 . 43 also tangent to circles around the effective pivot point 35 be arranged. You can also have one Having training, which sections of concentric circular cylinder lateral surfaces around the surface normal 36 correspond.

All of the actuator transducer stator electrodes 37 _i are on a support structure in the form of a substrate 39 arranged. They are particularly stationary on the substrate 39 arranged. They are in particular in a single, through the front of the substrate 39 arranged level defined. This level is also referred to as the actuator level or as a comb level.

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

The actuator transducer stator electrodes 37 _i are each in an area on the substrate 39 arranged, which on the one hand has a square outer envelope, on the other hand, a circular inner envelope. Alternatively, the actuator-converter stator electrodes 37 _i also in a circular area on the substrate 39 be arranged. Here, the outer envelope is circular. The individual actuator transducer stator electrodes 37 _In particular, _i are each arranged in circular ring-shaped regions. The total electrode structure, that is, all the actuator-stator electrodes 37 _i are arranged in a region which has an outer envelope, just that of the reflection surface of the single mirror 20 equivalent. It can also be arranged in a slightly smaller, in particular about 5% to 25% smaller area.

The electrode structure has a radial symmetry. In particular, it has a fourfold radial symmetry. The electrode structure may also have a different radial symmetry. It may in particular have a threefold radial symmetry. In particular, it has k-fold radial symmetry, where k is the number of actuator-transducer stator electrodes 37 _i indicates. Apart from the subdivision of the electrode structure into the different actuator transducer stator electrodes 37 _i , the electrode structure has an n-fold radial symmetry, n being just the total number of comb fingers 38 all actuator transducer stator electrodes 37 _i corresponds.

The individual actuator transducer stator electrodes 37 Apart from their different arrangement, _i are on the substrate 39 identically formed. This is not mandatory. They can also be designed differently. In particular, depending on the mechanical properties of the joint 32 be educated.

The comb fingers 38 are radial to the effective pivot point 35 , or radially to the alignment of the surface normal 36 in the untwisted neutral state of the single mirror 20 arranged.

For single mirrors 20 , whose mirror body 27 Dimensions of 1 mm x 1 mm, have the comb fingers 38 at its outer end in the radial direction has a thickness d of at most 5 microns. Generally, the maximum thickness d of the comb fingers 38 at its radially outer end in the range of 1 micron to 20 microns, in particular in the range of 3 microns to 10 microns.

The comb fingers 38 have a height h, that is, an extension in the direction of the surface normal 36 , in the range of 10 .mu.m to 100 .mu.m, in particular in the range of 20 .mu.m to 50 .mu.m. Other values are also conceivable. The height h is constant in the radial direction. It can also decrease in the radial direction. As a result, larger tilt angles can be made possible without this leading to the comb fingers of the actuator mirror electrode 42 hit the base plate.

Neighboring comb fingers 38 . 43 the actuator electrodes 37 _i on the one hand and the actuator mirror electrodes 42 on the other hand, in the untwisted state of the individual mirror 20 a minimum distance in the range of 1 .mu.m to 10 .mu.m, in particular in the range of 3 .mu.m to 7 .mu.m, in particular of about 5 .mu.m. For individual mirrors 20 with smaller or larger dimensions, these values can be scaled accordingly.

At this minimum distance m is the minimum distance between adjacent mirror and Storkkammfinger measured in the neutral, unverschwenkten state of the individual mirror 20 , At a tilt of the single mirror 20 the comb fingers can approach each other. The minimum distance m is chosen such that it is also at a maximum tilt of the individual mirror 20 does not come to a collision of adjacent mirror and Storkkammfinger. Here also manufacturing tolerances are considered. Such manufacturing tolerances are a few micrometers, in particular at most 3 .mu.m, in particular at most 2 .mu.m, in particular at most 1 .mu.m.

The maximum possible approximation of neighboring comb fingers 38 . 43 can be derived from the geometric details of the same and their arrangement as well as the maximum possible tilting of the individual mirror 20 determine in a simple way. In the present embodiment, the maximum approximation of adjacent comb fingers 38 . 43 at a tilt of the individual mirror 20 around 100 mrad about 2 μm. 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 act with an actuator mirror electrode 42 together. The actuator mirror electrode 42 is with the mirror body 27 connected. The actuator mirror electrode 42 is in particular mechanically fixed to the mirror body 27 connected. The actuator-transducer mirror electrodes 42 form a counter electrode to the actuator transducer stator electrodes 37 _i . They are therefore also referred to simply as the counter electrode.

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

The actuator mirror electrode 42 is complementary to the actuator transducer stator electrodes 37 _i trained. In particular, it forms a ring with actuator-transducer mirror comb fingers 43 , which in the following simplifying as a mirror comb finger or merely as a comb finger 43 be designated. The mirror comb fingers 43 the actuator mirror electrode 42 correspond in their geometric properties substantially the stator comb fingers 38 the actuator transducer stator electrodes 37 _i .

All of the comb fingers 38 . 43 can have the same height h, ie identical dimensions in the direction of the surface normal 36 exhibit. This facilitates the manufacturing process.

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

The comb fingers 38 . 43 may have a radially decreasing height h. It is also possible the comb fingers 38 . 43 in the region of the corners of the optical component 30 shorter than the other comb fingers 38 . 43 , This allows a larger tilt angle of the individual mirror 20 be enabled.

The actuator mirror electrode 42 is in particular designed such that in each case one of the comb fingers 43 the actuator mirror electrode 42 in a space between two of the comb fingers 38 the actuator transducer stator electrodes 37 _{i can} dive.

The actuator mirror electrode 42 is electrically conductive with the mirror body 27 connected. Your comb fingers 43 are therefore equipotential. The mirror body 27 is connected via an electrically conductive hinge spring low resistance to the base plate. In principle, one can also use the mirror substrate, that is the mirror body 27 , the actuator mirror electrodes 42 and sensor mirror electrodes 45 via separate supply lines via the solid-state joint 32 Individually electrically connect and so for example, to different potentials or decouple in terms of interference and / or crosstalk. The base plate may be on earth but does not have to. Alternatively, the mirror can be electrically decoupled from the mirror plate via a conductive hinge spring on another connected to a voltage source. This makes it possible to apply the mirror with a fixed or variable bias voltage.

The actuator transducer stator electrodes 37 _i are for pivoting the single mirror 20 acted upon by an actuator voltage U _A. The actuator transducer stator electrodes 37 _i , therefore, also become active actuator transducer stator electrodes 37 _i denotes. For acting on the actuator converter stator electrodes 37 _i with the actuator voltage U _A , a voltage source not shown in the figures is provided. The actuator voltage U _A , is at most 200 volts, in particular at most 100 volts. By appropriate action on a selection of the actuator transducer stator electrodes 37 _i with the actuator voltage U _A can the individual mirror 20 be tilted from a neutral position by up to 50 mrad, in particular up to 100 mrad, in particular to 150mrad. Alternatively, the actuators can also be controlled with a charge source (current source).

The Different Actuator Converter Stator Electrodes 37 _i can be used to pivot the individual mirror 20 be acted upon with different actuator voltages U _Ai . To control the actuator voltages U _Ai a control device not shown in the figures is provided.

For tilting one of the individual mirrors 20 is applied to one of the actuator transducer stator electrodes 37 _i an actuator voltage U _A applied. At the same time, with respect to the surface normal 36 opposite actuator transducer stator electrode 37 _j a deviating actuator voltage U _A2 ≠ U _A1 created. Here, U _A2 = 0 volts. In particular, it is possible to use only one of the actuator-stator electrodes 37 _i to apply to the actuator voltage U _A1 , while all other actuator-stator electrodes 37 _{j be kept} at a voltage of 0 volts.

At a tilt of the single mirror 20 dive the comb fingers of the actuator mirror electrode 42 on one side, in particular in the region of the actuator transformer stator electrode acted upon by the actuator voltage U _A 37 _i lower between the comb fingers 38 this actuator-converter stator electrode 37 _i . On the opposite side of the tilt axis 33 dips the actuator mirror electrode 42 less deep into the actuator transducer stator electrodes 37 _j . It may even lead to an at least partial removal of the actuator mirror electrode 42 from the actuator transducer stator electrodes 37 _j come.

The comb overlap, that is the immersion depth of the actuator mirror electrode 42 between the actuator-stator electrodes 37 _i is at a mirror dimension of about 0.5mm × 0.5mm in the neutral position of the single mirror 20 30 μm.

For detecting the pivoting position of the individual mirror 20 a sensor device with a sensor unit and a shielding unit is provided. The sensor device may be part of the actuator device 31 form.

The sensor unit comprises four sensor electrodes 44 ₁ to 44 ₄ .

The sensor electrodes 44 ₁ to 44 ₄ are in the variant according to 3 each in the corners of the substrate 39 arranged. They are outside the ring of the actuator electrodes 37 _i arranged. At the in 3 variant shown are the sensor electrodes 44 ₁ to 44 ₄ relative to the tilt axes 33 . 34 of the joint 32 arranged offset by 45 °.

The sensor electrodes 44 _i are designed as comb electrodes. The sensor electrodes 44 i each comprise a transmitter electrode 47 and a receiver electrode 48 , Both the transmitter electrode 47 as well as the receiver electrode 48 have a comb structure. In particular, they comprise a plurality of comb fingers. The comb fingers of the transmitter electrode 47 are in particular alternating with the comb fingers of the receiver electrode 48 arranged.

In addition, the sensor device comprises for each of the sensor electrodes 44 _i a shielding unit 45 , The shielding unit 45 includes shielding elements 46 in the form of comb fingers. The shielding unit 45 is according to a counter electrode suitable for the sensor electrodes 44 _i trained. It is fix with the mirror body 27 connected. It is in the corners of the mirror body 27 arranged. At a tilt of the single mirror 20 can the shielding unit 45 different deep between the comb fingers of the sensor electrodes 44 _i dive. This results in a variable shielding of adjacent comb fingers. This causes the capacitance between the adjacent comb fingers of the sensor electrodes 44 _i at a pivoting of the individual mirror 20 changes. The capacity change can be measured. For this purpose, the inputs of a measuring device are alternating with the comb fingers of the sensor electrodes 44 _i connected.

The following is with reference to the 6 a further variant of the optical component 30 described. The optical component 30 according to the in the 6 schematically represented variant corresponds to one of the previously described variants, to which reference is hereby made.

According to the in 6 schematically illustrated variant is provided on the joint 32 in the direction of the surface normals 36 opposite side of the mirror body 27 a balance weight 64 to arrange. The balance weight 64 is fix with the mirror body 27 connected. It is especially direct with the mirror body 27 connected.

The balance weight 64 is formed and arranged such that the center of mass 65 the mechanical system, which all together with the mirror body 27 of the single mirror 20 movable components of the optical component 30 includes, just with the effective pivot point 35 coincides. Through a targeted training and arrangement of the balance weight 64 can be the center of mass 65 be selectively shifted. By shifting the center of mass 65 such that its position coincides with that of the effective pivot point 35 coincidence, the sensitivity of the individual mirror to external disturbances can be significantly reduced. In addition, parasitic eigenmodes are kept in a high-frequency range, which is sufficiently far from the frequency spectrum, which in a shift of the individual mirror 20 occur by means of the actuator device are removed.

By means of the balance weight 64 can be achieved that the center of mass 65 of the mechanical system, which inherently out of the effective pivot point 35 of the joint 32 can be shifted out, in the effective pivot point 35 is moved back.

The balance weight 64 can move in the direction of the surface normal 36 have a length of up to 500 microns, in particular up to 1mm.

For more details of this variant, see the DE 10 2015 204 874.8 directed.

The following is a method of manufacturing the mirror array 19 , in particular the optical components 30 with the individual mirrors 20 described. Generally, the optical devices are 30 around microelectromechanical devices (MEMS devices). It may or may not be micromirrors. The use of the method according to the invention for producing micromirrors is merely one advantageous application possibility of the method according to the invention, in particular in connection with projection exposure systems for microlithography, in particular for EUV lithography.

The mirror arrays 19 are densely packed with individual mirrors 20 which each have a complex three-dimensional structure. The individual mirrors 20 are in particular each with the joint 32 , the actuator device 31 , the sensors 44 , application specific integrated circuits (ASICs) as well as horizontal and vertical data and / or power lines provided. Most of these ingredients are in the finished mirror array 19 inaccessible. They are in particular inaccessible inside the optical components 30 arranged. According to the present invention, the optical components are provided 30 , especially the individual mirrors 20 to form from several separate joining parts, which are joined together only after the production of functional structures or parts thereof. The individual mirrors 20 In other words, they are first produced in a disassembled state. In each case, two or more parts to be joined 71 . 72 made separately. The parts to be joined 71 . 72 are each made by vertical structuring steps. The parts to be joined 71 . 72 contain in particular exclusively convex, exposed and accessible elements.

As previously described, the functional structures are mechanical and / or electrical structures.

The parts to be joined 71 . 72 be in a joining step 73 together. In particular, they are joined together after the functional structures have been produced. Optionally, a release step for releasing the movable part or parts can then be provided.

The production process according to the invention offers the advantage of a faster production and a higher yield. It is possible in particular, the joining parts 71 . 72 in parallel processes. It is possible in particular, several parts to be joined 71 . 72 in independent processes, especially at the same time.

The parts to be joined 71 . 72 can be tested before joining. In particular, they may be subjected to quality control prior to assembly. This can be faulty joining parts 71 . 72 be sorted out.

The parts to be joined 71 . 72 can be made by mass micro-machining (volume micro-mechanics).

The parts to be joined 71 . 72 are joined together by one or more bonding steps, in particular so-called wafer-level bonding steps. After assembly, detachment steps for releasing the moving parts and / or separating steps can be provided.

The parts to be joined 71 . 72 have full CMOS compatibility.

The parts to be joined 71 . 72 are in particular made of monocrystalline silicon or of multilayer substrates 74 . 75 , which layers or at least regions of monocrystalline silicon, produced. According to the invention, it has been recognized that monocrystalline silicon has advantageous, and in particular, predictable and reproducible mechanical, electrical and thermal properties. Especially the joints 32 with the bending springs 50 . 51 and / or the mirror body 27 and / or the comb fingers 38 . 43 may be at least partially, in particular completely, made of monocrystalline silicon.

The method according to the invention will be described below in connection with the production of the optical components described above 30 described with circular comb electrodes. This represents merely an exemplary special case. The inventive method is correspondingly also suitable for the production of components, in particular MEMS components, in particular MEMS mirrors with an alternative structure, in particular with an alternative actuator and / or sensor concept.

The optical component 30 with the individual mirror 20 and the actuator device 31 and sensor device 44 with comb electrodes serves as an example of a complex, truly three-dimensional structure. In this case, a true three-dimensional structure should be understood in particular to mean that the functional structures, in particular the actuator and / or sensor electrodes, do not lie in a common functional plane but in a direction perpendicular to a common plane, in particular to a plane parallel to the reflection surface of the single mirror 20 , an extension of at least 30 .mu.m, in particular at least 50 .mu.m, in particular at least 70 .mu.m. The extent in the direction perpendicular to the reflection surface of the individual mirror 20 can be at least 0.1 times, in particular 0.2 times, in particular at least 0.3 times, in particular at least 0.4 times, in particular at least 0.5 times as large as one Edge length of the reflection surface of the individual mirror 20 ,

In the following, an exemplary sequence of the manufacturing steps for the production of the optical component 30 , in particular for the production of the parts to be joined 71 . 72 , described. In the 7A to 7E and 9A to 9K To illustrate the method according to the invention, in each case a sequence of intermediate products during the production of the first joining part 71 ( 7A to 7E ) or the second joining part 72 ( 9A to 9K ). In the 12A to 12E further process steps are shown, which at both joining parts 71 . 72 when merging the same and then performed.

For the production of the first part to be joined 71 from the first substrate 74 in particular, vertical structuring steps, in particular exclusively vertical structuring steps, are provided. For the production of the second joining part 72 from the second substrate 75 are vertical structuring steps, in particular exclusively vertical structuring steps, provided. For the production of the first part to be joined 71 In particular, etching steps are provided exclusively, in particular isotropic and / or anisotropic etching steps and / or reactive ion etching.

As a starting point for the production of the first part to be joined 71 serves the first substrate 74 , The first substrate 74 is multi-layered. It includes a first layer 76 of silicon dioxide and two opposite sides of the first layer 76 arranged layers 77 . 78 , The layers 77 . 78 are made of silicon, in particular of monocrystalline silicon. At the first substrate 74 in other words, it is a so-called silicon-on-insulator wafer (SOI wafer, silicon on insulator wafer).

The layers 77 . 78 point in the direction of a surface normal 89 each an extent of the order of 100 microns. They can be made equally thick. You can also be designed differently thick. Their extension in the direction of the surface normals 89 is in particular at least 20 .mu.m, in particular at least 30 .mu.m, in particular at least 50 .mu.m, in particular at least 100 .mu.m. In particular, it is at most 1 mm, in particular at most 500 μm, in particular at most 300 μm.

The upper layer 77 serves to form the mirror body 27 , The lower layer 78 serves to form functional structures, in particular the comb fingers 43 the actuator device 31 ,

The first substrate 74 is also referred to as a mirror wafer.

In a first etching step 79 be openings 80 in the lower position 78 and the silicon dioxide layer 76 etched. To determine the position of the openings 80 a mask of photoresist is provided. The openings 80 serve to provide electrical access and contact with the mirror body 27 to accomplish.

The openings 80 between the comb fingers 43 allow electrical contact between the actuator and / or sensor comb fingers 43 and the mirror body 27 passing through the upper layer 77 is formed. The openings 80 can in the first etching step 79 as a circumferential ring structure, that is as a contiguous opening 80 , be formed. The opening / openings 80 point in the direction perpendicular to the surface normal 89 a width of a few microns.

In a subsequent filling step 81 be the openings 80 filled with doped polycrystalline silicon. Then the free surface of the lower layer 78 smoothed out again. For this purpose, a chemomechanical polish (CMP) is provided.

Optionally, silicon dioxide deposits may be provided 82 over the side openings 80 to dismiss the positions of the comb fingers 43 define. For the deposition of silicon dioxide deposition 82 In particular, a plasma-enhanced chemical vapor deposition (PECVD) process can be provided.

The silicon dioxide separation 82 at the position of the later comb fingers 43 is optional. It can be used for double masking. This can change the position of the comb fingers 43 better, especially safer, to be predestined. Through the silicon dioxide separation 82 In particular, a lateral degradation of the mask 85 above the comb fingers 43 during vertical etching 88 be avoided. By means of the silicon dioxide separation 82 In particular, the precision for the production of the comb-fingers 43 be improved.

In a second etching step 83 then becomes a stage 84 in the lower position 78 etched. The stage 84 has a height which is just the difference between the height of the comb fingers 43 and the extent of the connection block 53 in the direction perpendicular to the reflection surface of the individual mirror 20 equivalent. For the second etching step 83 in turn becomes a mask 85 made of photoresist on the free surface of the lower layer 78 applied.

It also becomes optional in the second etching step 83 a mechanical adjustment structure 86 generated. The adjustment structure 86 is in an edge region, in particular laterally of the actual individual mirror 20 arranged. The adjustment structure 86 includes in particular a matrix-like arrangement of columns and holes. It preferably comprises cylindrical, in particular circular cylindrical holes, in particular blind-hole-like structures. It may also include tips or teeth aligned along the crystallographic planes of the silicon. In particular, the substrate may be a {100} substrate or a {110} substrate.

The adjustment structure 86 serves the exact alignment of the parts to be joined 71 . 72 relative to each other. In particular, it serves for the lateral adjustment of the joining parts relative to each other. This can damage the functional structuring, especially when joining the parts to be joined 71 . 72 be prevented.

After removing the mask 85 will be another mask 87 made of photoresist on the free surface of the lower layer 78 Applied to the location of the comb fingers 43 and the location of the upper connection block 53 of the joint 32 define. Then, in a third etching step 88 the monocrystalline silicon of the lower layer 78 except for the silicon dioxide layer 76 away. As a result, the movable actuator and / or sensor comb fingers 43 and the upper connection block 53 educated. The etched stop is the buried silicon dioxide layer 76 ,

The ratio of the thickness of the layers 77 . 78 in the direction of the surface normals 89 to their extension in the direction perpendicular to the surface normal 89 is in particular at least 0.1, in particular at least 0.2, in particular at least 0.3. Especially with mirrors 20 with an edge length of less than 1 mm, the ratio may be 0.5 or more. It is usually less than 1.

After the third etching step 88 the mirror wafer has the mirror body 27 , the upper comb structure with the movable actuator and / or sensor comb fingers 43 and the upper spring-holding blocks in the form of the connecting blocks 53 on. In addition, the mirror wafer has the alignment or alignment structures 86 on. The mirror wafer is thus ready to be joined together with an actuator wafer, in particular to be bonded together.

The term mirror wafer here is not only for the first substrate serving as a starting point 74 or for the finished first joining part 71 but also for all intermediates (see 7B to 7D ) used.

The actuator and / or sensor comb fingers 43 form a special example of a functional structure of the first part to be joined 71 , They contribute in particular to the function of the first joining part 71 comprehensive optical component 30 , in particular the displaceability of the individual mirror 20 , or for detecting the displacement position of the same at.

For the production of the second joining part 72 from the second substrate 75 are vertical structuring steps, in particular exclusively vertical structuring steps, provided. For the production of the first part to be joined 71 In particular, etching steps are provided exclusively, in particular isotropic and / or anisotropic etching steps and / or reactive ion etching.

The following is with reference to the 9A to 9K the sequence of process steps for the production of the second joining part 72 from the second substrate 75 described. The second substrate serving as a starting point 75 , the finished second joining part 72 as well as the intermediates are also referred to as actuator wafers. This is used in particular to delineate against the intermediate stages of the first joining part 71 which, as previously described, are also referred to as mirror wafers.

As a starting point for the production of the second joining part 72 also serves an SOI wafer. The SOI wafer comprises a buried silicon dioxide layer 90 , an upper layer 91 and a lower layer 92 , The upper layer 91 and the lower layer 92 are on opposite sides of the silicon dioxide layer 90 arranged. They are in particular made of monocrystalline silicon.

The lower layer 92 forms a holding wafer. It is also referred to as a holding substrate.

The upper layer 91 is also referred to as device position or functional position. Their thickness, that is, their extension in the direction of a surface normal 94 , just corresponds to the thickness of the lower connection block 52 which from this location 91 will be produced.

In the lower position 92 are vias 93 (TSVs, through silicon vias) provided.

The vias 93 are in the lower position 92 arranged. The respective outer of the vias 93 serves for the electrical connection of the comb electrodes to be produced, in particular the actuator electrodes 37 _i and / or the sensor electrodes 44 _i .

The electrical connection to the comb fingers 38 the actuator electrodes 37 _i can act as a ring-shaped structure in the lower layer 92 be formed of the actuator wafer. The ring may be divided into a number of separate segments, the number of different segments being just the number of actuator electrodes 37 _i corresponds. The individual segments are mutually isolated from each other. In addition, for the sensor electrodes 44 _i additional segments or separations between them may be provided. The segments are each electrically isolated from each other. The segments are isolated from the substrate by an SiO ₂ layer deposited on the sidewalls; they can be filled in particular with doped polycrystalline silicon. The trench structure for the via 93 has a width, for example, in the range of 1/20 to 1/10 of the thickness of the lower layer 92 lies. For the preparation of the trench structure for the via 93 For example, a deep reactive ion etching (DRIE) method with a high etch rate may be provided.

The electrical connection to the lower connection blocks 52 is also in this embodiment as a silicon via 93 educated. The lower connection blocks 52 can be electrically connected or grounded independently. Alternative training is possible and will be described in more detail below.

In a first etching step 95 become trenches 96 in the upper position 91 etched (see 10 ). The trenches 96 surround the lower connection blocks 52 , They also surround the one through the two spiral springs 50 . 51 formed cruciform structure 49 ,

The trenches 96 are filled in with tetraethylorthosilicate (TEOS). Then the free surface of the upper layer 91 smoothed, if necessary.

In a deposition step 97 is on the free surface of the upper layer 91 a silicon dioxide layer 98 deposited. Instead of a deposition, a thermal oxidation can also be provided.

In a bonding step 99 becomes a second SOI wafer 100 on the silicon dioxide layer 98 bonded. At the bonding step 99 it can be anodic, direct or fusion bonding.

The second SOI wafer has a device layer 101 and a holding wafer 102 on. The device location 101 has an extension in the direction of the surface normal 94 on which just the extension of the spiral springs 50 . 51 optionally plus the extension of the stiffening element 55 equivalent.

In a second etching step 103 becomes the holding wafer 102 etched away.

In a structuring step 104 becomes the buried oxide layer 105 of the second SOI wafer 100 structured. After the structuring step 104 covers the silicon dioxide layer 105 excluding the underlying cruciform structure 49 ,

The silicon below the cruciform structure 49 serves to increase the mechanical stability in the joining step described in more detail below for joining the mirror wafer and the actuator wafer. It must be surrounded on all sides by silicon dioxide, which forms an etch stop for the etching step, in which the silicon under the bending springs 50 . 51 with the exception of the lower connection block 52 is etched away.

In a third etching step 106 is - after applying a mask 107 made of photoresist - the silicon layer, that is the device layer 101 of the second SOI wafer 100 - Removed at the points where electrical contacts to the underlying structures, in particular the comb fingers 38 the actuator electrodes 37 _i and / or the sensor electrodes 44 _i and the lower connection blocks 52 , to be produced.

The third etching step 106 made contact openings can also to the lower layer 92 that is, to the support structure of the actuator wafer, are formed. In this case, the lower connection blocks 52 after filling the contact openings with polycrystalline silicon electrically conductive with the holding substrate, that is, the lower layer 92 of the actuator wafer, connected.

In a subsequent deposition step 108 becomes epi-polycrystalline silicon or polycrystalline silicon on the free surface of the upper layer 91 of the actuator wafer. The deposited silicon layer has a thickness in the direction of the surface normal 94 of about 11 microns. The thickness of the deposited silicon layer corresponds exactly to the difference between the extent of the comb fingers 38 the actuator electrodes 37 _i and / or sensor electrodes 44 _i in this direction and the sum of the lower connection blocks 52 and the bending springs 50 . 51 in this direction.

After the deposition step 108 The deposited silicon can be smoothed again.

In an optional further deposition step, in turn, silicon layer deposits 109 in the areas above the lower comb fingers to be trained later 38 be deposited. In particular, this can in turn be a PECVD method may be provided. For details, see the deposition of silicon dioxide deposits 82 directed.

Then - after applying a photoresist mask 110 in a further etching step 111 a step 112 etched into the deposited silicon. The stage 112 has an extension in the direction of the surface normal 94 which is just the difference between the extension of the comb fingers 38 and the connection blocks 52 in this direction corresponds. The height of the step 112 in the direction of the surface normals 94 is in particular about 7 microns. As an etch stop for the etching step 111 serves the silicon dioxide layer 105 , which above the spiral springs 50 . 51 is arranged.

In the etching step 111 also become adjustment and / or alignment structures 116 produced in an edge region next to the actual functional structures of the actuator wafer.

In a subsequent structuring step 113 , after applying a thickness mask 114 Made of photoresist, the comb fingers are used 38 the actuator electrodes 37 _i and / or sensor electrodes 44 _i structured (see 11 ). For this purpose, the silicon is etched away, wherein the silicon dioxide forms an etch stop. The structuring step 113 serves the training of the comb fingers 38 and the lower connection blocks 52 ,

In a further etching step 115 The remaining silicon dioxide is deposited over the spiral springs 50 . 51 and over the comb fingers 38 away.

Subsequently, the actuator wafer with the comb structures of the actuator electrodes 37 _i and / or sensor electrodes 44 _i and the monocrystalline bending springs 50 . 51 , which are on the lower connecting blocks 52 are arranged, ready to be assembled with the mirror wafer.

Before the two joining parts 71 . 72 can be put together, they can be subjected to a test procedure. It is in particular possible and provided, the joining parts 71 . 72 to test for proper operation before assembly. Faulty parts to be joined 71 . 72 can be sorted out and / or repaired.

Then the two joining parts 71 . 72 in a joining step 117 together. For this purpose, the mirror wafer and the actuator wafer are bonded to one another. They are bonded together in particular by means of a eutectic bonding method, a fusion bonding method or a direct bonding method.

After joining the parts to be joined 71 . 72 These form a wafer stack 121 , For bonding the parts to be joined 71 . 72 In particular, a eutectic Bodingverfahren can be provided. For eutectic bonding certain softer metals, such as aluminum or gold, may be provided. They support the simultaneous formation of contact with the different structures.

When assembling the mirror wafer with the actuator wafer, the accuracy of the relative alignment of these two joining parts 71 . 72 in the direction perpendicular to the surface normal 94 each other at least 5 microns, in particular at least 3 microns, in particular at least 2 microns, in particular at least 1 micron. That is, the actual alignment of the two parts to be joined 71 . 72 relative to each other is given and maintained with an uncertainty of less than 3 microns, especially less than 2 microns, especially less than 1 micron. This can be achieved in particular by the interaction, in particular the intermeshing of the alignment and alignment structures 86 . 116 be achieved. The accuracy of joining the two parts to be joined 71 . 72 in the direction of the surface normals 94 is preferably correspondingly good. It can also be better in principle. It can also be a bit lower.

The parts to be joined 71 . 72 In particular, they are joined in such a way that there is no undesired collision of the functional structures, in particular the comb fingers 38 . 43 comes.

The adjustment structures 86 . 116 prevent lateral movement. In particular, they prevent the comb fingers 38 . 43 get in touch.

The recesses of the adjustment structures 86 . 116 are deep enough that they do not affect the contacting of the contact surfaces between the mirror wafer and the actuator wafer.

When assembling the mirror wafer and the actuator wafer comes the upper connection block 53 in contact with the spiral spring 51 , The joint 32 in particular, by joining the upper connection block 53 with the spiral spring 51 educated.

When joining it comes in particular to an overlap 118 the comb finger 43 . 38 the upper and lower comb electrodes. The overlap 118 is illustrated in the figures by dashed lines. The overlap 118 the comb finger 38 . 43 in the direction of the surface normals 89 respectively 94 is in particular at least 10 .mu.m, in particular at least 20 .mu.m, in particular at least 30 .mu.m, in particular at least 40 .mu.m, in particular at least 50 microns.

After assembly further processing steps can be provided.

In a further etching step 119 can after applying a mask 120 from photoresist a cruciform structure from the back of the wafer stack 121 vertically into the silicon below the spiral springs 50 . 51 be etched. The cross-shaped structure is a few microns narrower than the extension of the spiral springs 50 . 51 in the direction perpendicular to the surface normal 94 ,

In a further etching step 122 continues through the buried silicon dioxide layer 90 etched as well as by the silicon below the cruciform structure 49 with the bending springs 50 . 51 (please refer 13 ). Here, the same mask 120 as in the etching step 119 be used.

The silicon dioxide layer 98 below the spiral springs 50 . 51 forms an etch stop for the etching step 122 ,

The remaining silicon up to the side walls defined by buried oxide layers can be removed laterally, for example by isotropic silicon etching, in particular with SF ₆ .

In a further etching step 123 For example, the silicon dioxide which is not required can be removed, for example by etching in hydrofluoric acid vapor vapor (HF vapor etching).

Like from the 12A to 12E is qualitatively apparent, are the functional structures of the optical device 30 , especially the comb-fingers 38 . 43 the actuator device 31 and the sensor device and the bending structure or the joint, after joining the joining parts 71 . 72 in the joining step 117 no longer freely accessible, but inaccessible.

The following is with reference to the 14A to 14F and 15A to 15B an alternative to the production of the second joining part 72 described. Only deviating process steps are described. Incidentally, reference is made to the method described above.

According to the alternative, it is provided that the silicon material below the bending springs 50 . 51 to remove by undercutting. For this purpose, a XeF ₂ silicon sacrificial etching process can be provided.

For this purpose, first the lower connection blocks 52 and the area of sacrificial silicon 124 through vertical trenches 125 , which are etched into the silicon and filled with tetraethyl orthosilicate (TEOS) laterally defined (see 14A and 15A ).

In the 14B . 14C and 15B is the Aktuatorwafer shown in the intermediate state, in which the position with the bending springs 50 . 51 with the second substrate 75 is bonded and the cruciform structure 49 with the bending springs 50 . 51 is defined. In addition, in these figures already a protective layer 126 from SiO ₂ , which was applied to protect the functional structures thereon. All functional structures on the mirror wafer and the actuator wafer are by means of the protective layer 126 passivated.

Subsequently, as described above with the joining step 117 continued. The thus obtained intermediate is in the 14D shown. Schematically indicated herein is in particular the overlap 118 between the comb fingers 43 the mirror wafer and the comb fingers 38 of the actuator wafer.

In a subsequent etching step 170 the silicon volume in the circular area around the bending structure, in particular the sacrificial silicon 124 below the cruciform structure 49 with the bending springs 50 . 51 away. As an etching step 170 In particular, an isotopic etching step is provided. In particular, an etching with XeF ₂ gas can be provided. The intermediate product thus obtained is shown schematically in 14E shown.

In a subsequent removal step 127 becomes the protective layer 126 away. For this purpose, an etching process with hydrofluoric acid is provided.

The finished component is shown schematically in FIG 14F shown.

The following is with reference to the 16A to 26 a method for producing the optical component 30 with a balance weight 64 described. With regard to basic properties of the method, reference is made to the preceding description.

Like in the 16A is shown, serves in this alternative as a starting point for the production of the first joining part 71 a first substrate 74 , which is designed as a double SOI wafer. The mirror wafer thus according to this alternative, in addition to the silicon dioxide layer 76 and the layers arranged opposite one another 77 and 78 another silicon dioxide layer 128 and a silicon layer disposed thereon 129 ,

The middle silicon layer 77 has a thickness in the direction of the surface normal 89 on which just the extension of the mirror body 27 in this direction corresponds. The lower layer 78 points in the direction of the surface normal 89 a thickness indicative of the extent of the upper comb fingers 43 equivalent.

On the bottom of the lower layer 78 is another silicon dioxide layer 130 applied. The silicon dioxide layer 130 serves as a stop for chemo-mechanical polishing (CMP).

In a first etching step 131 become trenches and / or holes 132 at the points in the silicon and silicon dioxide layers 76 . 78 . 130 etched to which electrical contacts between the lower layer 78 and the middle location 77 to be produced. These are, for example, the electrical connections to the upper comb fingers 43 and / or electrical connections to the mirror body 27 through the joint 32 ,

In a filling step 133 The trenches / holes are filled with doped polycrystalline silicon. Then, the silicon dioxide layer 130 away.

In a subsequent etching step 134 becomes the vertical step 84 in the lower position 78 etched. This is done with the mask 85 Mistake. For further details, see the previous description (see 7D ).

Accordingly, with respect to the subsequent manufacture of the comb fingers 43 and the upper connection blocks 53 to the previous description (see in particular 7E and related description).

Then the mask becomes 87 away.

As in the 16E and 16F is shown as an example, have the upper connection blocks 53 in this alternative, a smaller extent in the direction of the surface normal 89 on as the upper comb fingers 43 ,

In the 16A to 16F and 18A to 18K are the side areas with the adjustment and alignment structures 86 not shown. They are designed and provided as in the embodiment according to the preceding description.

As a starting point for the production of the second joining part 72 serves the second substrate 75 , which is formed substantially according to the preceding description. The upper layer 91 has an extension in the direction of the surface normal 94 of for example 40 μm. The extension corresponds in particular just the extension of the lower connection blocks 52 up to the bending springs 50 . 51 , The lower layer 92 However, in this alternative has a much greater extension in the direction of the surface normal than in the alternative described above. The lower layer 92 In particular, an extension in the direction of the surface normal 94 in the range of 300 microns to 1 mm. In particular, it has an extension in the direction of the surface normal 94 on which the extension of the balance weight 64 equivalent.

Then it is on the upper layer 91 a silicon dioxide layer 136 applied. In these are ditches and / or holes 137 etched. The trenches and / or holes 137 extend to the vias 93 ,

You will be in a subsequent refill step 138 filled with doped polycrystalline silicon. Then, the silicon dioxide layer 136 away.

In a subsequent structuring step 139 become trenches 140 in the upper position 91 etched and then filled with TEOS. As a result, three types of structures are insulated in the lateral direction by silicon dioxide: fixed connection blocks 52 , Connecting blocks between the mirror body 27 and the balance weight 64 and a sacrificial silicon volume under the suspension, which includes bending springs (see 19 ).

Then in the bonding step 141 a double SOI wafer 143 with a silicon dioxide layer 142 joined together on the side to be bonded with the actuator wafer. The double SOI wafer 143 includes two oxide layers 144 . 145 , a lower device location 146 , a medium device location 147 and a holding wafer 148 ,

The lower device position 146 has an extension in the direction of the surface normal 94 which just corresponds to the thickness of the spring structures. The thickness may in particular be about 1.5 μm.

The middle device position 147 has a thickness of about 20 microns. Its thickness corresponds in particular just the thickness of the plate-shaped structure of the suspension of the mirror body 27 ,

The upper oxide layer 144 may be of oxide, in particular SiO ₂ . It serves as an etch stop for a subsequent etching step 149 , in which the holding wafer 148 is completely removed.

In a subsequent etching step 150 is with the help of a mask, not shown in the figures of photoresist, wherever electrical contacts are to be made, except for the upper layer 91 etched down. Here are the upper oxide 144 , the middle device location 147 , the oxide layer 145 , the lower device position 146 and the silicon dioxide layer to be bonded 142 removed (see 20 ).

Electrical contacts should in particular in the range of the later lower comb fingers 38 getting produced.

In addition, the aforementioned locations in the areas are etched away, at which a subsequent DRIE step all layers of the silicon dioxide layer 19 should remove.

In a deposition step 151 For example, doped polycrystalline silicon becomes that in the etching step 150 deposited etched areas. This can be done by epitaxial deposition. Subsequently, the surface can be chemo-mechanically polished, with the upper oxide layer 144 serves as a stop.

In the reactive ion etching method (DRIE method) provided below, the comb fingers become 38 , the fixed and the moving blocks as well as the plate-shaped structure of the suspension of the mirror body 27 educated. Here is a mask 154 made of photoresist. There is only one DRIE step provided.

The spring structures need not be masked. The oxide layer serves as etch stop over the defect structures 145 ,

The 18I and 18J show different sections through the actuator wafer according to the DRIE method 152 , The orientation of the cuts is in the 21 indicated by the letters I and J.

In the following removal step 155 becomes the mask 154 removed, in particular stripped (see 22 ).

Subsequently, the mirror wafers and actuator wafer are ready to be aligned and mated relative to each other. According to a preferred embodiment is provided, the individual Fügteile 71 . 72 to test before assembly, in particular to test their proper function.

Until the mirror wafer and the actuator wafer are joined in the joining step 117 can the two parts to be joined 71 . 72 parallel, that means being processed at the same time. As a result, the total time required for the production of the optical component can be reduced by up to 50%.

The further manufacturing steps include the joining step 117 for producing the wafer stack 121 and further processing of the wafer stack 121 ,

To join in the joining step 117 become the mirror wafer, that is the first joining part 71 , and the actuator wafer, that is, the second adherend 72 , in the direction perpendicular to the surface normal 89 respectively 94 aligned with each other. They can be prebound in the relatively aligned arrangement, that is, fixed relative to each other.

Then the two wafers, that is, the two parts to be joined 71 . 72 , in the joining step 117 to the wafer stack 121 joined together, in particular bonded. Like from the 23B is qualitatively apparent, the entire mechanical suspension of the mirror body 27 supported by massive silicon structures at this stage of the process. It is therefore protected by the silicon volume from damage by the bonding pressure.

In a subsequent lithography step, the gap becomes 157 between the substrate 39 and the balance weight 64 defined (see 24 ). In addition, here are the pie-like structures 158 below the mirror body 27 firmly connected blocks and the access opening 159 below the silicon base 160 below the suspension of the mirror body 27 Are defined. The gap 157 as well as the access opening 159 become in the lower situation by a DRIE procedure 92 brought in. They have a width to height / depth ratio in the range of 1:15 to 1:10. Subsequently, the buried silicon dioxide layer 90 etched away.

In a subsequent passivation step 161 All open, interior surfaces are deposited by depositing a layer 162 made of silica passivated. The silicon dioxide layer 162 is deposited from a gas phase, in particular in the form of TEOS or by means of an LPCVD process.

In a subsequent etching step 163 With high substrate bias to increase the etching anisotropy, only silica, which is on horizontal surfaces, especially a bottom of the 157 and the access opening 159 , is etched away. Here are the vertical side walls 164 the gap 157 passivated and thus protected from the subsequent etching step.

When etching 163 becomes an access channel to a volume of sacrificial silicon 166 created. In a subsequent etching step 165 under xenon fluoride (XeF ₂ ) is the sacrificial silicon 166 under the suspension 167 of the mirror body 27 with the spring structures and the stronger suspension plate removed. The remaining functional structures are from this etching step 165 not affected, since the volume with the sacrificial silicon 166 surrounded by a silicon dioxide layer on all sides except the access opening 159 , All other silicon surfaces are passivated.

In an optional bonding or bonding step, a capping wafer may be applied to the backside of the device 30 that is, on the mirror body 27 opposite side of the lower layer 92 to be applied.

In a further etching step 168 becomes the silicon layer 129 on the front of the mirror body 27 away. The final dissolution or exemption step 169 serves to release the bending structures of the joint 32 as well as the mirror body 27 , For this purpose, an etching process in hydrofluoric acid vapor is provided (see 15 and 26 ).

The procedures described above are not intended to be exhaustive or to conclude. They merely serve to explain a sequence of exemplary method steps in the production of the optical component 30 , Alternative or further method steps, in particular further post-processing steps, are possible. It is of course provided in particular, the mirror body 27 still to be provided with a suitable coating, in particular an EUV-reflective coating. Details for this are known in the art.

Substantial advantages of the methods according to the invention are again summarized below in the following:
The methods according to the invention make it possible to produce a component, in particular an optical component, in particular a micromirror component as an example of a MEMS, with a complex three-dimensional structure.

The methods according to the invention make it possible to produce a component, in particular an optical component, in particular a micromirror component as an example of a MEMS, with electrical and / or mechanical functional structures which are arranged inside the component and are therefore inaccessible from the outside.

The methods of the invention are particularly easy to control. They are based exclusively on process steps, in particular for the microstructuring of wafers, in particular of monocrystalline silicon wafers.

The monocrystalline silicon wafers, which are used as starting materials for the parts to be joined 71 . 72 and thus for the optical component 30 serve, have well-defined properties, which are independent of the individual process steps. In particular, they have predictable and precisely reproducible properties. These can be issued by the wafer supplier.

The monocrystalline silicon has a high thermal conductivity, in particular in comparison to other forms of silicon, in particular polycrystalline silicon.

The inventive method allow parallelization, that is, a simultaneous production of the different parts to be joined 71 . 72 ,

The methods according to the invention enable production of the parts to be joined 71 . 72 regardless of their joining.

The methods of the invention are CMOS compatible.

The processes according to the invention comprise fewer process steps than conventional production processes. The inventive methods lead to a considerable time savings in the production of the optical component 30 , Compared to a conventional production method in which functional structures are produced by applying layers and then structuring them, the total number of method steps for producing the optical component can be more than 50%, in particular more than 60%, in particular more than 70%. In particular, be reduced by up to 80%.

The inventive methods lead to significantly reduced costs for the optical component 30 ,

The processes according to the invention lead to a higher yield (production yield) in the production of the optical components 30 ,

In addition, the process steps are better controllable than in conventional production processes.

The optical component produced according to the invention 30 , especially the individual mirror 20 , is characterized structurally in that the functional structures, especially the comb-fingers 38 . 43 , are made of monocrystalline silicon. In particular, they are of real three-dimensional design, that is to say they have an extension in the direction parallel to the surface normals 89 . 94 which is at least 10 μm, in particular at least 20 μm, in particular at least 30 .mu.m, in particular at least 50 .mu.m, in particular at least 100 .mu.m, in particular at least 200 microns. The extension in the direction parallel to the surface normals 89 . 94 is in particular at least 5%, in particular at least 10%, in particular at least 20%, in particular at least 30%, in particular at least 40%, in particular at least 50% of the lateral extension of the individual mirrors 20 , in particular their edge length in the direction perpendicular to the surface normal 89 . 94 ,

The comb fingers 38 . 43 have an overlap (z) in the direction of the surface normal 89 . 94 which is at least 5 μm, in particular at least 10 μm, in particular at least 20 μm, in particular, at least 30 μm, in particular at least 30 μm, in particular at least 40 μm.

Regarding the lateral distance of the comb fingers 38 . 43 Please refer to the previous description. The comb fingers 38 . 43 are in particular over the entire pivoting range of the individual mirror 20 spaced apart, ie collision-free.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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

• WO 2012/130768 A2 [0002, 0099]
• DE 102013204546 A1 [0002]
• WO 2010/049076 A2 [0086]
• EP 1225481 A2 [0090]
• DE 102013206529 A1 [0105]
• DE 102015204874 [0156]

Claims (18)

Method for producing a microelectromechanical component ( 20 . 30 ) with at least one moving component, comprising the following steps: 1.1. Providing a first substrate ( 74 ) for producing a first joining part ( 71 1.2. Providing at least one second substrate ( 75 ) for producing at least one second joining part ( 72 ), 1.3. Producing the first part to be joined ( 71 ) with first functional structures ( 43 . 53 ) from the first substrate ( 74 1.4. Producing the second joining part ( 72 ) with second functional structures ( 50 . 51 . 52 . 38 ) from the second substrate ( 75 1.5. Assembly of the joining parts ( 71 . 72 ), 1.5.1. where the joining parts ( 71 . 72 ) are joined together with an accuracy better than 5 μm 1.6. Triggering at least one movable component from at least one of the parts to be joined ( 71 . 72 ). Method according to claim 1, characterized in that the functional structures ( 53 . 38 ) after joining the parts to be joined ( 71 . 72 ) has an overlap (z) of at least 5 μm in the direction parallel to a central surface normal ( 89 ) of the first substrate ( 74 ) exhibit. Method according to one of the preceding claims, characterized in that the functional structures ( 53 . 38 ) comprise the at least one movable component which, over its entire range of motion, is collision-free with the remaining components of the microelectromechanical component ( 20 . 30 ). Method according to one of the preceding claims, characterized in that at least a part of the first functional structures ( 43 . 53 ) with at least a part of the second functional structures ( 50 . 51 . 52 . 38 ) after joining the parts to be joined ( 71 . 72 ) or form common functional structures. Method according to one of the preceding claims, characterized in that the joining parts ( 71 . 72 ) are assembled in such a way that the functional structures ( 43 . 53 ; 50 . 51 . 52 . 38 ) are inaccessible after assembly. Method according to one of the preceding claims, characterized in that for the production of at least one of the joining parts ( 71 . 72 ) from one of the substrates ( 74 . 75 ) each vertical structuring steps are provided. Method according to one of the preceding claims, characterized in that the functional structures ( 43 . 53 . 50 . 51 . 52 . 38 ) are formed real three-dimensional. Method according to one of the preceding claims, characterized in that the first functional structures are comb fingers ( 43 ) of a first comb electrode and the second functional structures comb fingers ( 38 ) comprise a second comb electrode, wherein the second comb electrode after joining the joining parts ( 71 . 72 ) forms a counter electrode to the first comb electrode. Method according to one of the preceding claims, characterized in that the joining parts ( 71 . 72 ) are produced in parallel processes. Method according to one of the preceding claims, characterized in that the joining parts ( 71 . 72 ) are subjected to a test process before assembly. Micromirror ( 20 . 30 ) for a micromirror array ( 19 ) of a projection exposure apparatus ( 1 ): 11.1. a first joining part ( 71 11.1.1. which a mirror body ( 27 ) and 11.1.2. at least a first functional structure ( 43 . 53 ), 11.2. at least one second joining part ( 72 11.2.1. which has a carrying structure ( 92 ) and 11.2.2. at least one second functional structure ( 50 . 51 . 52 . 38 ), 11.3. where the joining parts ( 71 . 72 ) are bonded together in a joint area, and 11.4. where at least the functional structures ( 43 . 53 . 50 . 51 . 52 . 38 ) are at least partially made of monocrystalline silicon. Micromirror ( 20 . 30 ) according to claim 10, characterized in that the functional structures ( 43 . 53 . 50 . 51 . 52 . 38 ) an extension in the direction parallel to a central surface normal ( 89 ) of the micromirror ( 20 . 30 ), which at least 5% of an extension of the mirror body ( 27 ) in the direction perpendicular thereto. Micromirror ( 20 . 30 ) according to one of claims 11 or 12, characterized in that the mirror body ( 27 ) relative to the support structure ( 92 ) is displaceable, the functional structures ( 43 ) of the first part to be joined ( 71 ) and the functional structures ( 38 ) of the second joining part ( 72 ) over the entire range of motion of the mirror body ( 27 ) have a predetermined minimum distance from each other. Micromirror array ( 19 ) for a projection exposure apparatus ( 1 ) with a plurality of micromirrors ( 20 . 30 ) according to any one of claims 11 to 13. Optical system for a projection exposure apparatus ( 1 ) comprising at least one facet mirror ( 13 . 14 ) with a micromirror array ( 19 ) according to claim 14. Projection exposure apparatus ( 1 ) for microlithography 16.1. an optical system according to claim 15, and a 16.2. Projection optics ( 7 ) for mapping an object field ( 5 ) in an image field ( 8th ). A method of manufacturing a micro- or nanostructured device comprising the following steps: 17.1. Providing a projection exposure apparatus ( 1 ) according to claim 16, 17.2. Providing a substrate, on which at least partially a layer of a photosensitive material is applied, 17.3. Providing a reticle with structures to be imaged, 17.4. Projecting at least a portion of the reticle onto a portion of the photosensitive layer by means of the projection exposure apparatus ( 1 ), 17.5. Developing the exposed photosensitive layer.  Component produced by a method according to claim 17.

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