Device for use in the manufacture of MEMS mirror arrays

Abstract

The invention relates to devices (200) that are helpful for the production of MEMS mirror arrays (100), such as those used in semiconductor technology equipment. The device (200) serves to temporarily protect the spaces between MEMS mirror arrays (100), particularly for semiconductor technology systems, with a predetermined number of individual mirror elements (101) adjustable by at least one degree of freedom relative to a common base structure (104) during large-area machining of the mirror elements (101), wherein an actuable mechanism (103) required for adjustment is arranged directly below each mirror element (101). For this purpose, the device (100) comprises at least one sealing element (300), which is arranged at least temporarily such that the at least one substructure space (210) comprising the actuable mechanisms (103) is sealedly separated from a machining space (220) comprising the mirror surfaces (102) of the mirror elements (101).

Description

[0001] The invention relates to devices that are helpful for the production of MEMS mirror arrays, such as those used in semiconductor technology equipment.

[0002] In the prior art, semiconductor technology equipment refers to equipment used for the production or testing of microstructured devices or the components required for their manufacture. An example of such equipment is a projection exposure system for photolithography.

[0003] Photolithography is used to manufacture microstructured components, such as integrated circuits. The projection exposure system used comprises an illumination system and a projection system. The image of a mask (also called a reticulum) illuminated by the illumination system is projected by the projection system onto a substrate, for example, a silicon wafer, coated with a photosensitive layer and positioned in the image plane of the projection system. This reduces the size of the mask structure, transferring it onto the photosensitive coating of the substrate.

[0004] In illumination systems, particularly projection illuminators designed for EUV applications (i.e., with exposure wavelengths from 5 nm to 30 nm), two faceted mirrors are typically positioned in the beam path between the actual exposure radiation source and the mask to be illuminated. These mirrors, operating on a principle similar to that of a honeycomb condenser, homogenize the radiation. The faceted mirror closer to the exposure radiation source is often a field faceted mirror, while the other is a pupil faceted mirror.

[0005] To produce different intensity and / or angle-of-incidence distributions when illuminating the mask, it is known to form the facets of at least one of the two faceted mirrors – in particular those of the field faceted mirror – from one or more electromechanically individually pivotable micromirrors. A corresponding method is disclosed, for example, in WO 2012 / 130768 A2.

[0006] In order to achieve a small size for the individual micromirrors, it is known to form groups of micromirrors in the form of a so-called MEMS mirror array, namely a mirror array made of microelectromechanical systems (MEMS).

[0007] In a MEMS mirror array, a multitude of small mirror elements are mounted so that they can be moved individually relative to a common base. At least one actuator is provided for each mirror element, allowing it to be adjusted along a predefined degree of freedom. Often, the mirror elements can be pivoted about two axes perpendicular to each other and parallel to the base. In such cases, sufficient actuators are provided to allow the mirror elements to pivot independently about these axes. Sensors can also be provided for the individual mirror elements to determine their position or tilt relative to the base, thus enabling monitoring of the mirrors' alignment. A particularly advantageous embodiment for the mirrors of a MEMS mirror array is described in DE 10 2015 204 874 A1.

[0008] A method for manufacturing a micromirror or a MEMS mirror array comprising a plurality of such micromirrors is disclosed in DE 10 2015 220 018 A1, together with further details on a possible embodiment of the micromirror.

[0009] The production of MEMS mirror arrays may require the processing of the mirror surfaces of individual mirror elements using large-area methods, for example, to apply a coating or to remove a layer remaining from a previous manufacturing step. Such methods may need to be performed at a stage of the manufacturing process where the mirror elements are no longer fixed but are already movable, or where the mechanics required for this movement are fully completed.

[0010] With methods that affect large areas, there is a risk at a correspondingly late stage in the fabrication of MEMS mirror arrays that the substances used, e.g., coating material or etchants, can penetrate the spaces between the individual mirror elements and affect the components located behind the mirror elements. For example, coating material penetrating these areas can reduce the mobility of a mirror element and / or cause electrical short circuits; penetrating etchants can unintentionally weaken the structure.

[0011] The object of the present invention is to create devices with which the problems known from the prior art can be avoided or at least reduced to a considerable extent.

[0012] This problem is solved by a device according to claim 1. Advantageous further developments are the subject of the dependent claims.

[0013] Accordingly, the invention relates to a device for the temporary protection of the spaces between MEMS mirror arrays, in particular for semiconductor technology systems, with a predetermined number of individual mirror elements adjustable by at least one degree of freedom relative to a common basic structure during large-area machining of the mirror elements, wherein an actuable mechanism required for adjustment is arranged directly below each mirror element, and wherein at least one sealing element is temporarily arranged such that the at least one substructure space comprising the actuable mechanisms is sealed off from a machining space comprising the mirror surfaces of the mirror elements.

[0014] First, some terms used in connection with the present invention will be explained.

[0015] The term "mirror surfaces" refers to those surfaces of a mirror element that, after completion of the mirror element or the MEMS mirror array, form the reflective surface that is productively used when the MEMS mirror array is in operation. In particular, the mirror surface need not yet possess reflective properties at the time of use of the invention during the manufacture of a MEMS mirror array. Rather, it is possible, for example, to provide the mirror surface with a reflective coating using the device according to the invention.

[0016] "Actuable mechanics" refers to those components that enable and can effect the movement of mirror elements within predefined degrees of freedom (e.g., tilting). Such mechanisms therefore include not only the joints, guides, and / or mounts fundamentally required for movement, but also actuators with which a desired movement can be generated. Sensors may also be incorporated to determine the current position or tilt of a mirror element.

[0017] By using the at least one sealing element provided according to the invention, one or more substructure spaces are created in which at least the actuable mechanisms of the individual mirror elements are arranged, and which are separated from the processing space in which the mirror surfaces of the mirror elements are arranged, the mirror surfaces can be processed without negatively affecting the actuable mechanisms. This allows for both coating and processing of the mirror surfaces with etching agents: The at least one sealing element prevents the substances used in the processing from penetrating the at least one substructure space and causing undesirable effects there.

[0018] Depending on the specific design of the at least one sealing element, the additional benefit of transport protection can also be achieved. The actuated mechanisms of a MEMS mirror array are very sensitive to shock and can be damaged by external impacts or similar events, such as those that can occur during transport. This damage primarily results from the movement of the mirror elements caused by the impacts. The at least one sealing element can prevent or at least significantly reduce the movement of the mirror elements due to impacts, thereby also lowering the risk of damage to the actuated mechanisms during transport.

[0019] At least one sealing element can be arranged between the mirror elements such that the resulting substructure space encompasses the actuable mechanisms of a plurality of mirror elements. This at least one sealing element can be arranged between the end faces, and thus between the non-machinable mirror surfaces of adjacent mirror elements. It is possible, and even preferred, if at least one sealing element separates a substructure space from the machining area, encompassing the actuable mechanisms of all mirror elements. The sealing can also be achieved by a single, grid-like sealing element extending over the entire MEMS mirror array.

[0020] It is also possible that, in at least one mirror element, a sealing element is arranged between the mirror element and the base structure in such a way that the resulting enclosed substructure space encompasses the actuating mechanism of the mirror element. The substructure space separated by such a sealing element comprises exclusively the actuating mechanism of the mirror element to which the sealing element is attached. In such a design, all mirror elements will typically need to be equipped with a corresponding sealing element.

[0021] The sealing element may be irreversibly removable. In other words, once removed, the sealing element cannot be reinstalled, or not without unreasonable effort. This also applies to any attempt to manufacture a new sealing element on site.

[0022] An irreversibly removable sealing element can be a material bridge spanning between two mirror elements or between a mirror element and the base structure, which must be at least partially removed or destroyed to remove the sealing element. The material bridge is preferably made of a material that does not negatively affect the intended machining process of the mirror surface and can also be reliably removed after machining. It is essential to ensure that the sealing element material does not outgas, particularly if a vacuum and / or an elevated temperature of up to approximately 200°C is present at least temporarily in the machining area. The material for the material bridge can be a material known from semiconductor manufacturing, such as silicon or silicon dioxide, or alternatively, a metal.Suitable materials regularly exhibit appropriate properties, even with regard to typical processing procedures for the mirror surface. Furthermore, methods are known for removing the sealing element material with the required precision without damaging the mirror elements or the subsequently processed mirror surfaces.

[0023] At least one sealing element can also be made of a material that contracts when irradiated with a predetermined wavelength. If such a material covers a gap between two mirror elements or a gap between a mirror element and the base structure, the material can be reduced by appropriate irradiation to such an extent that an open gap is created, allowing movement of the mirror elements. In the exemplary embodiments mentioned, the material can remain permanently bonded to an adjacent element, such as one of the mirror elements or the base structure. However, it is also possible for the sealing element to be removed from the MEMS mirror array after the material has completely contracted.

[0024] It is also possible that at least one sealing element is a reversibly sealing element, i.e., a sealing element that can be reversibly changed to be either sealing or not. The sealing element can also be designed as a fully or partially reversibly removable sealing element.

[0025] At least one sealing element can be designed as an inflatable element. In its inflated state, the sealing element can then, for example, form a force-fit connection against opposite end faces of two adjacent mirror elements. To remove the sealing element, pressure is released, thereby breaking the force-fit and allowing the sealing element to be removed. If a corresponding sealing element is created by joining, for example by welding or bonding several films or similar materials, the joining points are preferably arranged away from the areas intended for force-fit.

[0026] At least one sealing element can also include a piezoelectric element, which bends or shortens when the applied voltage changes. It can be designed so that, under no-load conditions, the piezoelectric element attached to a mirror element or the base structure extends to and rests against another mirror element. When a suitable voltage is applied, the piezoelectric element can deform in such a way that it releases from contact with the other mirror element. As a result, the mirror elements can then move freely.

[0027] It is also possible that at least one sealing element comprises a material with inverse thermal expansion. Similar to a material that contracts upon irradiation with a predetermined wavelength, a corresponding seal can be achieved by targeted temperature control – in this case, reversibly. The sealing element is preferably designed such that it contracts sufficiently at the operating temperature of the MEMS mirror array to allow the individual mirror elements to move freely. If a seal is desired, the temperature should be appropriately reduced.

[0028] Regardless of the design of at least one sealing element, it may be advantageous to have a circumferential frame extending towards the base structure on the mirror element. If a sealing element is to act directly between two adjacent mirror elements, this increases the contact area available for the sealing element. If a sealing element is to act between the mirror element and the base structure, the distance to be bridged can be shortened by a corresponding frame.

[0029] It is also possible, of course, to arrange at least one frame extending from the base structure towards a mirror element. Such a frame can also reduce the gap between the mirror element and the base structure, which may need to be bridged by a sealing element. It is also possible to provide frames on both the base structure and the mirror element.

[0030] The invention will now be described by way of example with reference to advantageous embodiments and the accompanying drawings. These show: Fig. 1: A schematic representation of a projection exposure system for photolithography comprising MEMS mirror arrays; and Fig. 2-9: Schematic representations of devices according to the invention.

[0031] In Fig. Figure 1 shows a projection exposure system 1 for photolithography as an example of a system for semiconductor technology in a schematic meridional section. The projection exposure system 1 comprises an illumination system 10 and a projection system 20.

[0032] The illumination system 10 illuminates an object field 11 in an object plane or reticulum plane 12. The illumination system 10 comprises an exposure radiation source 13, which, in the illustrated embodiment, emits illumination radiation comprising at least useful light in the EUV range, i.e., in particular with a wavelength between 5 nm and 30 nm. The exposure radiation source 13 can be a plasma source, for example, an LPP source (laser-produced plasma) or a DPP source (gas-discharge-produced plasma). It can also be a synchrotron-based radiation source. The exposure radiation source 13 can also be a free-electron laser (FEL).

[0033] The illumination radiation emanating from the light source 13 is first focused in a collector 14. The collector 14 can be a collector with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one reflective surface of the collector 14 can be illuminated at grazing incidence (GI), i.e., with angles of incidence greater than 45°, or at normal incidence (NI), i.e., with angles of incidence less than 45°. The collector 14 can be structured and / or coated to optimize its reflectivity for the useful radiation and to suppress stray light.

[0034] After the collector 14, the illumination radiation propagates through an intermediate focus in an intermediate focal plane 15. If the illumination system 10 is to be constructed in a modular manner, the intermediate focal plane 15 can, in principle, be used for the separation – including structural separation – of the illumination system 10 into a radiation source module, comprising the exposure radiation source 13 and the collector 14, and the illumination optics 16 described below. With such a separation, the radiation source module and the illumination optics 16 then together form a modularly constructed illumination system 10.

[0035] The illumination optics 16 include a deflecting mirror 17. The deflecting mirror 17 can be a flat deflecting mirror or, alternatively, a mirror with an effect that influences the beam shape beyond the mere deflection effect. Alternatively or additionally, the deflecting mirror 17 can be designed as a spectral filter that separates a useful wavelength of the illumination radiation from stray light of a different wavelength.

[0036] The deflecting mirror 17 deflects the radiation from the illumination radiation source 13 onto a first faceted mirror 18. If the first faceted mirror 18 is arranged – as in the present case – in a plane of the illumination optics 16 that is optically conjugate to the reticular plane 12 as a field plane, it is also referred to as a field faceted mirror.

[0037] The first faceted mirror 18 comprises a plurality of micromirrors 18' that can be individually pivoted about two mutually perpendicular axes for the controllable formation of facets. Each micromirror is equipped with an orientation sensor (not shown) for determining its orientation. The first faceted mirror 18 is therefore a microelectromechanical system (MEMS system), as described, for example, in DE 10 2008 009 600 A1.

[0038] In the beam path of the illumination optics 16, a second faceted mirror 19 is arranged downstream of the first faceted mirror 18, resulting in a double-faceted system, the basic principle of which is also known as a honeycomb condenser (fly's eye integrator). If the second faceted mirror 19 is arranged in a pupil plane of the illumination optics 16 – as in the illustrated embodiment – ​​it is also referred to as a pupil faceted mirror. However, the second faceted mirror 19 can also be arranged at a distance from a pupil plane of the illumination optics 16, in which case the combination of the first and second faceted mirrors 18, 19 results in a specular reflector, as described, for example, in US 2006 / 0132747 A1, EP 1 614 008 B1, and US 6,573,978.

[0039] The second faceted mirror 19 need not be constructed from pivotable micromirrors, but can instead comprise individual facets formed from one or a manageable number of mirrors that are significantly larger than micromirrors, and which are either fixed or tiltable only between two defined end positions. However, as shown, it is also possible to provide the second faceted mirror 19 with a microelectromechanical system comprising a plurality of micromirrors 19' that are individually pivotable about two axes perpendicular to each other, each preferably including an orientation sensor.

[0040] With the aid of the second faceted mirror 19, the individual facets of the first faceted mirror 18 are projected onto the object field 11, although this is regularly only an approximate projection. The second faceted mirror 19 can be the last beam-shaping or even the last mirror for the illumination radiation in the beam path before the object field 11.

[0041] Each of the facets of the second faceted mirror 19 is assigned to exactly one of the facets of the first faceted mirror 18 to form an illumination channel for illuminating the object field 11. This can result in illumination according to Köhler's principle.

[0042] The facets of the first faceted mirror 18 are each superimposed by a corresponding facet of the second faceted mirror 19 to illuminate the object field 11. The illumination of the object field 11 is as homogeneous as possible. It preferably exhibits a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0043] By selecting the illumination channels ultimately used, which is easily achieved by appropriately adjusting the micromirrors 18' of the first faceted mirror 18, the intensity distribution in the entrance pupil of the projection system 20 described below can also be adjusted. This intensity distribution is also referred to as the illumination setting. Furthermore, it can be advantageous not to arrange the second faceted mirror 19 exactly in a plane that is optically conjugate to a pupil plane of the projection system 20. In particular, the pupil faceted mirror 19 can be tilted relative to a pupil plane of the projection system 20, as described, for example, in DE 10 2017 220 586 A1.

[0044] During the Fig. In the arrangement of the components of the illumination optics 16 shown in Figure 1, the second faceted mirror 19 is arranged in a surface conjugate to the entrance pupil of the projection system 20. Deflection mirror 17 and the two faceted mirrors 18, 19 are arranged at an angle both to the object plane 12 and to each other.

[0045] In an alternative embodiment of the illumination optics 16, not shown, a transmission optic comprising one or more mirrors can be provided in the beam path between the second faceted mirror 19 and the object field 11. The transmission optic can, in particular, comprise one or two mirrors for normal incidence (NI mirrors) and / or one or two mirrors for grazing incidence (GI mirrors). With an additional transmission optic, different positions of the entrance pupil for the tangential and sagittal beam paths of the projection system 20 described below can be accommodated.

[0046] Alternatively, it is possible that on the in Fig. The deflecting mirror 17 shown in Figure 1 is dispensed with, for which the faceted mirrors 18, 19 are then to be arranged appropriately opposite the radiation source 13 and the collector 14.

[0047] Using the projection system 20, the object field 11 in the reticulum plane 12 is transferred to the image field 21 in the image plane 22.

[0048] The projection system 20 comprises a plurality of mirrors M. i , which are numbered according to their arrangement in the beam path of the projection exposure system 1. Regarding the mirrors M i These are optical elements 25.

[0049] In the Fig. In the example shown, the projection system 20 comprises six mirrors M1 to M6 as optical elements 25. Alternatives with four, eight, ten, twelve or another number of mirrors M iare also possible. The penultimate mirror M5 and the last mirror M6 each have a passage for the illumination radiation, making the depicted projection system 20 a doubly obscured optic. The projection system 20 has an image-side numerical aperture that is greater than 0.3 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0050] The reflective surfaces of the mirrors M i can be designed as freeform surfaces without an axis of rotational symmetry. Alternatively, the reflective surfaces of the mirrors M can be i but can also be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflecting surface shape. The mirrors M iLike the mirrors of the lighting optics 16, they can have reflective coatings for the illumination radiation. These reflective coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0051] The projection system 20 has a large object-image offset in the y-direction between a y-coordinate of the center of the object field 11 and a y-coordinate of the center of the image field 21. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 12 and the image plane 22.

[0052] The projection system 20 can in particular be anamorphic, i.e. it has in particular different image scales β x , β y in the x and y directions. The two image scales β x , β y of the projection system 20 are preferably located at (β x , β y) = (+ / - 0.25, / +- 0.125). A magnification β of 0.25 corresponds to a reduction in the ratio of 4:1, while a magnification β of 0.125 results in a reduction in the ratio of 8:1. A positive sign for the magnification β indicates a magnification without image inversion, a negative sign indicates a magnification with image inversion.

[0053] Other magnification ratios are also possible. Magnification ratios with the same sign and those with the same absolute value β are also possible. x , β y In the x and y directions, adjustments are possible.

[0054] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 11 and the image field 21 can be the same or different, depending on the design of the projection system 20. Examples of projection systems 20 with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 A1.

[0055] Projection system 20 can, in particular, have a homocentric entrance pupil. This may be accessible. However, it may also be inaccessible.

[0056] A reticle 30 (also called a mask) arranged in the object field 11 is exposed by the lighting system 10 and transferred to the image plane 21 by the projection system 20. The reticle 30 is held by a reticle holder 31. The reticle holder 31 can be moved, particularly in a scanning direction, by means of a reticle displacement drive 32. In the illustrated embodiment, the scanning direction is in the y-direction.

[0057] The reticle 30 can have an aspect ratio between 1:1 and 1:3, preferably between 1:1 and 1:2, and particularly preferably 1:1 or 1:2. The reticle 30 can be substantially rectangular and is preferably 5 to 7 inches (12.70 to 17.78 cm) long and wide, more preferably 6 inches (15.24 cm) long and wide. Alternatively, the reticle 30 can be 5 to 7 inches (12.70 to 17.78 cm) long and 10 to 14 inches (25.40 to 35.56 cm) wide, and is preferably 6 inches (15.24 cm) long and 12 inches (30.48 cm) wide.

[0058] A structure on the reticulum 30 is imaged onto a photosensitive layer of a wafer 35 located in the image plane 22 within the image field 21. The wafer 35 is held by a wafer holder 36. The wafer holder 36 can be displaced, particularly along the y-direction, via a wafer transfer drive 37. The displacement of the reticulum 30 via the reticulum transfer drive 32 and of the wafer 35 via the wafer transfer drive 37 can be synchronized.

[0059] The in Fig. The projection exposure system 1 shown in Figure 1, or its illumination system 10, the preceding description of which essentially reflects known prior art, is characterized in that the first and / or second faceted mirror 18, 19 comprises one or more MEMS mirror arrays 100 manufactured according to the invention. Each of the MEMS mirror arrays 100 has a plurality of individual mirror elements 101, each independently adjustable by two degrees of rotational freedom, which are arranged in a two-dimensional grid. Each of the faceted mirrors 18, 19 can be formed by a single MEMS mirror array 100 or by several MEMS mirror arrays 100 arranged side by side.

[0060] In Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. Figure 9 shows a schematic cross-sectional view of a portion of a MEMS mirror array 100, initially depicting the state at a stage of the manufacturing process before a reflective coating is applied to the mirror surface 102 of the mirror elements 101. The illustrations therefore also include devices 200 according to the invention. If the devices include reversible sealing elements 300, the left side of each figure shows how the sealing elements 300 can be temporarily repositioned to disengage from the sealing function, while the right side shows the sealing position of the sealing elements 300.

[0061] The mirror elements 101 each have reflective mirror surfaces 102 at least at the end of the manufacturing process of the MEMS mirror array 100. In the previous example, the mirror surfaces 102 are provided with a coating that reflects EUV radiation with a wavelength of 13.5 nm. To align the mirror surfaces 102, the mirror elements are connected via Fig. 2-9 actuated mechanisms 103, shown only schematically, are arranged on a common fixed base structure 104 and are tiltable by two degrees of freedom. The mechanisms 103 comprise at least one articulated bearing, actuators, and sensors. Supply lines, parts of the control electronics for the actuators, etc., can be arranged on the base structure 103. This is known from the prior art and requires no further explanation here. To allow the individual mirror elements 101 to be adjusted independently and without mutual interference, a space 105 is provided between each of the individual mirror elements 101.

[0062] In the version according to Fig. 2 In the area of ​​each mirror element 101, a frame 240 is provided, extending from the base structure 104 towards the respective mirror element 101. The gap remaining between the frame 240 and the mirror element 101 is closed with a removable sealing element 300, namely a material bridge 310.

[0063] The frames 240 and sealing elements 300 create a number of substructure spaces 210 corresponding to the number of mirror elements 101, each containing the actuable mechanism 103 of the associated mirror element 101. Since the substructure space 210 is sealed tightly against the environment, and in particular the processing space 220, by the frames 240 and sealing elements 300, processing steps such as coating the mirror surfaces 102 of the mirror elements 101 located in the processing space 220 can be carried out without the risk of the coating material used penetrating the actuable mechanism 103.

[0064] At the same time, the mirror elements 101 are connected by the frames 203 and sealing elements 300 in the Fig. The position shown in section 2 is maintained, thus ensuring transport safety.

[0065] After the mirror surfaces 102 have been processed and / or if no transport securing is required, the sealing elements 300 can be removed, allowing the mirror elements 101 to move within the degrees of freedom provided by the actuating mechanism 103. The dimensions of the sealing elements 300 and the frame 240 are chosen such that the frame 240 does not restrict the movement of the mirror elements 101.

[0066] The sealing element 300 is preferably made of a material or metal known from semiconductor manufacturing. Various methods, particularly from semiconductor manufacturing, are known in the prior art for removing sealing elements 300 made of such a material without damaging the remaining structure and / or coatings, etc. The removal of the sealing elements 300 is generally irreversible.

[0067] In the version according to Fig. 3 is the framework 240 starting from the basic structure 104 (cf. Fig. 2) Frames 230 extending from each mirror element 101 towards the base structure 104 are provided. These frames 230 serve as a support surface for material bridges 310, which are provided as sealing elements 300 and are arranged directly between adjacent mirror elements 101. The sealing elements 300, together with the mirror elements 101 themselves, create a continuous subspace 210 in which the actuable mechanisms 103 of all mirror elements 101 are arranged and which is tightly separated from the machining space 220. The machining space 220, however, encompasses the mirror surfaces 102, thus allowing them to be machined without risk of damaging the actuable mechanisms 103.

[0068] The sealing elements 300 can, as already mentioned in connection with Fig. 2. Irreversibly removed. Reference is made to the relevant explanations.

[0069] The exemplary embodiment according to Fig. 4 is similar to the one from Fig. 3. Instead of a material bridge 310 as a sealing element 300, a grid-shaped inflatable sealing element 320 is provided, which, when inflated, forms a force-fit and sealing connection with the frame 230. To remove the sealing element 320, gas can be released, thereby releasing the force-fit and allowing the sealing element 320 to be removed.

[0070] In principle, it is possible to reattach the sealing element 320 at a later date, which is why this design variant can be considered reversible.

[0071] Furthermore, the statements regarding Fig. 3.

[0072] The same applies to the variant shown in the text. Fig. 5. Piezoelectric elements 330 are provided as sealing elements 300 between the frames 230 of the individual mirror elements. The piezoelectric elements 330 are designed such that, in a stress-free state, they completely seal the space between adjacent mirror elements 101 (right side of the Fig. 5) However, when a suitable voltage is applied, the piezo elements 330 contract, thereby loosening the sealing element 300 to such an extent that the mirror elements 101 are freely movable.

[0073] Corresponding piezo elements 330 are also used in the version variant according to Fig. 6 as sealing elements 300. However, in the stress-free state, the piezo elements 330 do not extend between adjacent mirror elements 101, but rather between the basic structure 104 and each mirror element 101 or a frame 230 arranged on it.

[0074] When the piezo elements 330 are de-energized, the mirror elements 101 are each fixed in place, and their actuating mechanisms are each enclosed in a sealed substructure 210. When sufficient voltage is applied, the piezo elements 330 contract sufficiently to release the mirror elements 101.

[0075] Instead of directly utilizing the contraction capabilities of piezo elements 330, these can also be used to bend sealing elements 300 by applying tension. In Fig. Figure 6 shows how a corresponding sealing element 300 can extend between two mirror elements 101 or the frame 230 arranged therein (right side). It also shows how the deformation of the sealing elements 300 caused by tension and the use of a piezoelectric effect can be designed (left side).

[0076] Of course, it is also possible here to provide the sealing elements 300 not between adjacent mirror elements 101, but rather between each mirror element 101 and the base structure 104. The same applies in Fig. Figure 8 shows that, in the unstressed state, the piezo elements 330 cover a gap between the frames 230 arranged on the mirror elements 101 and the frames 240 extending from the base structure 104 (right side). When a voltage is applied, the gap is released (left side).

[0077] In Fig. 9 is an example of the implementation of Fig. A similar example is shown. However, the sealing element 300 is not made of irreversibly removable material, but rather either of material 340, which contracts irreversibly when irradiated with a material-specific wavelength, or of a material 350 with inverse thermal expansion.

[0078] In their initial state, materials 340 and 350 seal the substructure spaces 210 against the processing space 220 (right side). With suitable irradiation or an increase in temperature, e.g., to operating temperature, materials 340 and 350 contract, thus releasing the mirror elements 101 (left side). In the case of material 350, which has inverse thermal expansion, this process is also reversible. For this to occur, the temperature simply needs to be lowered again appropriately. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2012 / 130768 A2

[0005] DE 10 2015 204 874 A1

[0007] DE 10 2015 220 018 A1

[0008] DE 10 2008 009 600 A1

[0037] US 2006 / 0132747 A1

[0038] EP 1 614 008 B1

[0038] US 6,573,978

[0038] DE 10 2017 220 586 A1

[0043] US 2018 / 0074303 A1

[0054]

Claims

[1] Device (200) for temporarily protecting the spaces between MEMS mirror arrays (100), in particular for semiconductor technology plants, with a predetermined number of individual mirror elements (101) adjustable by at least one degree of freedom relative to a common basic structure (104) during large-area machining of the mirror elements (101), wherein an actuable mechanism (103) required for adjustment is arranged directly below each mirror element (101), characterized by , that at least one sealing element (300) is arranged such that the at least one substructure space (210) comprising the actuable mechanisms (103) is sealedly separated from a processing space (220) comprising the mirror surfaces (102) of the mirror elements (101). [2] Device according to claim 1, characterized by, that at least one sealing element (300) is arranged between the mirror elements (101) such that the substructure space (210) thereby separated comprises the actuable mechanisms (103) of a plurality, preferably all, of the mirror elements (101). [3] Device according to any of the preceding claims, characterized by , that in at least one mirror element (101) a sealing element (300) is arranged between the mirror element (101) and the base structure (104) such that the enclosed substructure space (210) thus created includes the actuable mechanics of the mirror element (101). [4] Device according to any of the preceding claims, characterized by , that at least one sealing element (300) is an irreversibly removable sealing element (300). [5] Device according to claim 4, characterized by, that the sealing element (300) comprises a material bridge (310) spanning between two mirror elements (101) or between a mirror element (101) and the base structure (104), which must be at least partially removed or destroyed in order to remove the sealing element (300). [6] Device according to claim 4, characterized by , that at least one sealing element (300) comprises a material (340) that contracts when irradiated with a predetermined wavelength. [7] Device according to any of the preceding claims, characterized by , that at least one sealing element (300) is a reversibly sealing sealing element (300). [8] Device according to claim 7, characterized by , that the at least one sealing element (300) is designed as an inflatable element (320), preferably a tubular element at least in sections. [9] Device according to claim 7, characterized by, that at least one sealing element (300) comprises a piezo element which bends or shortens when the applied voltage changes. [10] Device according to claim 7, characterized by , that at least one sealing element (300) comprises a material (350) with inverse thermal expansion. [11] Device according to any of the preceding claims, characterized by , that a circumferential frame (230) extending towards the base structure (140) is formed on the mirror element (100), with which the bearing surface for a sealing element (300) is increased and / or the distance to be bridged by the sealing element (300) between the mirror element (101) and the base structure (104) is reduced. [12] Device according to any of the preceding claims, characterized by , that at least one frame (240) extending from the basic structure (104) in the direction of a mirror element (101) is formed.

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