Method for post-processing and processing of MEMS chip

Abstract

The invention relates to a post-processing method of a MEMS chip (100) and a processing method of a MEMS chip (100). In a method for post-processing a MEMS chip (100), the MEMS chip (100) comprises a MEMS structure (102) arranged on a carrier material (104) and has at least one protruding region of protruding material, which protrudes laterally beyond the region of the MEMS chip (100) provided with the MEMS structure (102), the at least one protruding region (105) being removed by separating the protruding material from the carrier material (104) of the MEMS chip. In order to process the MEMS chip (100) without protruding beyond a region (105) of the MEMS structure (102) arranged on the carrier material (104), in particular after the post-processing according to the invention has been carried out, at least one lateral recess (108) is provided in the carrier material (104), and the MEMS chip (100) is processed by means of a tool (600) which engages in the lateral recess.

Description

[0001] This application claims priority to German patent application 10 2023 203 941.9, filed on April 27, 2023, the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to post-processing methods for MEMS chips and processing methods for MEMS chips. Background Technology

[0003] Microelectromechanical systems (MEMS) are small components that combine micromechanical structures and electronic components into a single chip. MEMS chips can be manufactured in a manner comparable to microchips with integrated circuits. MEMS chips essentially consist of a carrier material on which the actual MEMS structure is arranged.

[0004] Typically, multiple MEMS chips are manufactured on a common wafer—again, comparable to microchips with integrated circuits. After the MEMS structure is fabricated, the wafer is appropriately diced to form individual MEMS chips, which can then be further used, and for example, integrated into larger components.

[0005] MEMS chips with protective covers are known to protect MEMS structures from environmental influences and mechanical damage, especially during further processing after the MEMS chip has been manufactured.

[0006] A preferred option known in the prior art is to apply a wafer with suitable recesses onto a wafer on which MEMS structures are disposed, such that the applied wafer abuts against a carrier material of the MEMS chip and is fixedly connected to the carrier material in the region between groups of MEMS structures, each group of MEMS structures being assigned to a MEMS chip. When the wafers already connected in this way are diced to form individual MEMS chips, a protective cap is then provided for each MEMS chip, extending over the MEMS structure of the MEMS chip and protecting them from environmental influences and mechanical damage.

[0007] In some MEMS chips, particularly those with optical functions, a protective cover can be provided during manufacturing to simplify handling the MEMS chip during integration into larger components (i.e., placing one or more MEMS chips on a packaging substrate). However, the protective cover should be removed periodically, at the latest after integration is complete, to ensure proper optical functionality of the MEMS chip.

[0008] For example, the conference paper "Temporary protective packaging for optical MEMS" by L. Bogaerts et al. (44th International Symposium on Microelectronics, October 9-13, 2011, Long Beach, CA, USA) describes an option to remove the protective cover of a MEMS chip again when necessary. For the fixed connection between the wafer that eventually forms the actual MEMS chip (on which MEMS structures are disposed) and the wafer with the recess that ultimately forms the protective cover, a thermally degradable adhesive is used. Once the protective cover needs to be removed, the adhesive is thermally degraded and the protective cover can be removed. The MEMS structure can then be freely accessed again.

[0009] An example of an optical MEMS chip is a MEMS mirror array, in which multiple small mirror elements are each mounted individually movable relative to a common base. For each mirror element, at least one actuator is provided, enabling the mirror element to be adjusted along separately predefined degrees of freedom. Depending on the application, the mirror elements may be pivotable, in particular, about two axes perpendicular to each other and extending parallel to the base. In this case, sufficient actuators are then provided to enable the mirror elements to pivot precisely about these axes independently of each other. Sensors may also be provided for individual mirror elements, enabling the determination of the mirror element's position relative to the base, allowing for monitoring of mirror alignment. A particularly advantageous embodiment of a mirror for a MEMS mirror array is described in DE 10 2015 204 874 A1.

[0010] The corresponding MEMS mirror arrays can be used to produce microstructured components, such as integrated circuits, by means of photolithography.

[0011] For photolithography in the production of microstructured components, projection exposure equipment is used, which includes an illumination system and a projection system. The projection system projects the image of a mask (also called a photomask) illuminated by the illumination system onto a substrate (e.g., a silicon wafer) coated with a photosensitive layer and arranged in the image plane of the projection system, in order to reduce the size of the mask and thereby transfer the mask structure to the photosensitive coating of the substrate.

[0012] Typically, in the case of illumination systems, particularly in projection exposure equipment designed for the EUV range (i.e., for exposure wavelengths from 5 nm to 30 nm, especially 13.5 nm), two faceted mirrors are arranged in the beam path between the actual exposure radiation source and the mask to be illuminated, and these mirrors allow for homogenization of the radiation in a manner substantially equivalent to the principle of a fly-eye condenser. The closer faceted mirror in the beam path of the exposure radiation source is typically a so-called field faceted mirror, and the other faceted mirror is a so-called pupil faceted mirror.

[0013] In order to produce different intensity and / or incident angle distributions during mask irradiation, at least one of the faceted mirrors—particularly the faceted mirror of a field faceted mirror—can be formed by multiple electromechanically pivotable micromirrors or correspondingly configured MEMS chips, particularly MEMS mirror arrays. The same is disclosed, for example, in WO 2012 / 130768 A2.

[0014] Especially at the exposure wavelength of 13.5 nm, the protective cover of the MEMS chip as currently implemented must be removed, because there is currently no protective cover that is sufficiently transmissive to radiation at this wavelength.

[0015] It has been found that even after the protective cover is removed, the frame remains around the actual MEMS mirror array, and because of this frame, the optimal fill factor cannot be achieved when assembling a faceted mirror made of multiple MEMS mirror arrays. The "fill factor" is a measure of integration density and represents the ratio of the reflective surface of the mirrors in a MEMS mirror array formed by individual mirrors to the total surface area of ​​the faceted mirrors (the so-called "fill factor").

[0016] The reduced integration density described above, using a faceted reflector as an example, can also be applied to other application areas and other types of MEMS chips. Summary of the Invention

[0017] Therefore, the object of the present invention is to provide a method that enables MEMS chips to be post-processed and further processed in such a way that, in particular, the disadvantage of reduced integration density known from the prior art no longer occurs or only to a reduced extent.

[0018] This objective is achieved by the method claimed in claims 1 and 13. The dependent claims relate to advantageous improvements.

[0019] Therefore, the present invention relates to a method for post-processing of a MEMS chip, the MEMS chip including a MEMS structure disposed on a carrier material, wherein at least one protruding region of the protruding material laterally protrudes beyond the area of ​​the MEMS chip on which the MEMS structure is disposed, wherein at least one protruding region is removed by separating the protruding material from the carrier material of the MEMS chip.

[0020] Furthermore, the present invention relates to a method for processing a MEMS chip without protruding beyond the area of ​​the MEMS structure disposed on a carrier material, particularly after post-processing according to the invention, wherein at least one lateral recess is provided in the carrier material, and the MEMS chip is processed by means of a tool engaged in one or more lateral recesses.

[0021] This invention recognizes that materials that laterally protrude beyond the actual MEMS chip and have no impact on the actual functionality of the MEMS chip can have an adverse effect on integration density, especially if multiple MEMS chips are to be arranged as closely as possible adjacent to each other. This is because the protruding areas in question, which typically contain only non-functional material, serve as unwanted spacers. Corresponding protruding areas are regularly present in MEMS chips. During the fabrication of the MEMS chip, a protective cover is provided, and then the protective cover is removed again before or during integration. However, those areas to which the protective cover was initially attached remain as protrusions outside the actual MEMS chip.

[0022] If, for example, the faceted mirrors of an illumination system used in projection exposure equipment consist of MEMS mirror arrays, where, in principle, but especially in the case of EUV illumination, the protective cover must be removed before or during integration (particularly the arrangement of the MEMS mirror arrays on the packaging substrate), then, due to protrusions, a distance is created between adjacent mirrors of two adjacent MEMS mirror arrays that is greater than the distance between mirrors in one MEMS mirror array. This not only adversely affects the fill factor of mirrors constructed in this way (e.g., faceted mirrors), but may also contribute to the generation of undesirable stray light, which may be generated due to reflection or scattering of incident radiation on the material in the protruding areas. Furthermore, the regularity of the protruding areas has the effect that the individually controllable mirrors of a faceted mirror system comprising multiple MEMS mirror arrays are not actually arranged in a uniform grid, making the configuration and control of such faceted mirrors more difficult. Similar disadvantages may also arise in other applications of MEMS chips.

[0023] Based on this insight, the present invention relates not only to a method by which existing protruding areas of a MEMS chip can be subsequently removed, but also to a method for processing MEMS chips that do not have any protruding areas—whether because they have been post-processed according to the present invention or because they are manufactured with substantially no protruding areas.

[0024] According to the present invention, existing but unwanted protruding areas are removed by separating the protruding material from the carrier material of the MEMS chip. Therefore, the protruding material is separated from the carrier material of the MEMS chip and can subsequently be removed without any problems.

[0025] To remove at least one protruding region, a continuous gap can be created between the protruding region and the carrier material of the MEMS chip. As a result of creating a continuous gap, the material in the protruding region is directly and completely separated from the carrier material of the MEMS chip, in which case a neat edge of the carrier material can usually be obtained.

[0026] At least one protruding region can also be removed by creating a predetermined fracture location between the carrier material of the MEMS chip and the protruding region, and then fracturing that predetermined fracture location. This offers the advantage that the material in the protruding region can be separated in a controlled manner, specifically by means of a tool that applies the force required for fracture, and then can also be removed directly. The predetermined fracture location can be obtained by weakening the structure in the region, either by partially removing the material or by weakening the material itself. If the predetermined fracture location to be created in the protruding region is made too large or constructed such that complete separation of the entire predetermined fracture location at once cannot be ensured, the protruding region can also be subdivided into individual segments that are separated from each other by creating gaps and / or predetermined fracture locations between them, so that these segments can be separated individually by disrupting the corresponding predetermined fracture locations between the protruding material and the carrier material.

[0027] The two alternatives described above regarding the separation of protruding materials can be combined. In this regard, for example in the case of a MEMS chip with multiple protruding regions, one portion can be removed in each case by creating a continuous gap, and another portion can be removed by creating a predetermined fracture location and subsequently fractured.

[0028] It is also conceivable to combine the two measures described for individual protruding areas: specifically, generating a predetermined fracture location for separating the protruding area may include creating a continuous gap in another area and obtaining a thin material bridge only in a small area, which is then used as the predetermined fracture location.

[0029] To avoid collisions between material separated from the carrier material, or particularly the MEMS structure on the carrier material (which may be damaged as a result), due to the creation of continuous gaps or due to the destruction of a predetermined fracture location, and the carrier material, suitable measures can be provided. For example, the material in the protruding region may be attached to a tool or the like before it separates from the carrier material, and may remain attached to the tool or the like even after separation, and can therefore be removed from the carrier material in a controlled manner.

[0030] To create a continuous gap and / or a predetermined fracture location, a sacrificial material disposed in the corresponding region and differing at least from the protruding material, and typically also from the carrier material, can be removed. The sacrificial material can be introduced during the fabrication of the MEMS chip such that, after its removal in the process according to the method of the invention, only the material bridges configured to create the predetermined fracture locations remain, or any structural connection between the carrier material and the material in the protruding region is eliminated, thereby creating a continuous gap. However, it is also possible to introduce the sacrificial material only after the fabrication of the MEMS chip, and optionally even after the MEMS chip is at least partially integrated into an arrangement within a larger component or on a packaging substrate, using a suitable structuring method.

[0031] The sacrificial material can preferably be removed by an etching process. In this embodiment variant, the sacrificial material is preferably selected such that it can be removed without residue by the etching method, in which the carrier material and the MEMS structure of the MEMS chip are particularly protected from corrosion. Those skilled in the art, knowing the materials used for the carrier material and the MEMS structure, can typically determine a suitable sacrificial material without further effort. In particular, if a directional etching method is intended to be used only from the side of the carrier material opposite to the MEMS structure, the carrier material can also be protected from damage during the etching process, at least in areas of the MEMS chip, by providing a suitable protective layer.

[0032] Furthermore, it can be specified that the MEMS chip is housed in an etched package for a period of time to remove sacrificial material by means of an etching process. This package spatially defines the volume to be filled with a suitable etching medium—specifically, an etching gas or etch liquid. In this case, the etched package preferably has an inlet and an outlet to allow flow of the etching medium within the volume defined by the etched package, which can accelerate the etching process. If a protective cover is provided and the etching medium is introduced into the area encapsulated by the protective cover, and can also be removed again, through channels pre-introduced into the protective cover or through openings created therein only briefly, in a manner that still spans the MEMS chip during the envisioned etching process. In this case, the protective cover itself serves as the etched package.

[0033] As an alternative to etching, the sacrificial material can be thermally decomposable. To remove the sacrificial material, the MEMS chip is then heated to a temperature sufficient to decompose the sacrificial material and thus create continuous gaps and / or predetermined fracture locations.

[0034] To create continuous gaps and / or predetermined fracture locations, and to remove material without residue, high-energy radiation is preferred. For this purpose, focused particle beams, particularly focused ion beams (FIBs), preferably focused gallium ion beams, can be used for ablation or gas-assisted etching, or high-energy lasers for laser ablation.

[0035] To generate a predetermined fracture location, the material in the region of the predetermined fracture location can be weakened in a targeted manner, preferably by radiation. Weakening can be achieved by altering the crystal structure, particularly by breaking down existing single-crystal and / or polycrystalline structures to form amorphous structures. For this purpose, laser beams or ion beams can be used, for example. In principle, internal weakening of the material can also be achieved by disrupting its structure by properly focusing a laser beam over which the material is transparent.

[0036] At least temporary weakening of the material in the region of the predetermined fracture site can also be achieved by reducing the density of the material through localized heating. The heat input required for this can be achieved, for example, by a suitable laser beam.

[0037] What all of the above methods, including radiation, have in common is that the beam required for reflection, particularly laser or particle beams, especially ion beams, is typically strongly focused to a point or line. However, the correspondingly focused radiation has (though usually very small) a numerical aperture that regularly prevents continuous gaps and / or predetermined break locations from being generated directly at the edges of the MEMS chip's carrier material, at least if the radiation can be introduced only perpendicularly to the carrier material (i.e., at an incident angle of 0°). Specifically, in this case, there is otherwise a risk that portions of the MEMS structure located at the edges of the MEMS chip will be struck and damaged by the incident beam due to their expansion. A suitable choice of incident angle—if adjustable—makes this risk reduced or completely avoided. As an alternative, a radiation source emitting a collimated beam (i.e., a beam with only parallel rays) can be used, which is confined to the desired site of action by a shielding mask. Depending on the range of the beam, particularly even linearly extending sites of action, can be irradiated simultaneously by a properly designed shielding mask.

[0038] If a predetermined fracture location has been established, fracture can be achieved by introducing shear stress and / or tensile stress, resulting in the separation of the protruding material from the carrier material, which can then be removed. Specifically, tensile stress is generated at the predetermined fracture location if the protruding material in the plane of the carrier material of the MEMS chip is pulled away from the carrier material; shear stress is generated if a counterforce perpendicular to the plane of the carrier material is applied to both the carrier material and the protruding material in each case, where the direction of the force acting on the carrier material is irrelevant. The force can act directly on either the carrier material or the protruding material. However, force can also be introduced indirectly onto the protruding material by acting on the protective cover that is still present at this time. Suitable pressing or pulling tools can be used for this purpose, with the pulling tool preferably connected to the part to be pulled by suction.

[0039] The predetermined fracture location can also be disrupted by altering the temperature and / or by introducing a temperature gradient. In particular, if the predetermined fracture location was created by weakening the material in that region, appropriately altering the temperature can cause fracture at that location. In this case, it is only necessary to ensure that temperature changes in the region of the predetermined fracture location, in its adjacent areas, and / or throughout the MEMS chip do not damage the carrier substrate or the MEMS structure.

[0040] As mentioned several times, at least one protruding region to be removed may initially be configured to attach a protective cap for the MEMS chip. The protective cap may have been removed before the material in the protruding region is separated; however, it is also possible that the protective cap is removed simultaneously with the protruding region. In other words, the protective cap is therefore intended to remain connected to the material to be separated when creating a continuous gap or breaking at a predetermined fracture point. Therefore, handling the separated material, especially avoiding damage to the MEMS structure due to impact, is generally easier.

[0041] The MEMS chip from which at least one protruding area is removed is preferably a MEMS mirror array, more preferably a MEMS mirror array for photolithography, and particularly preferably a MEMS mirror array for EUV lithography. The latter is distinguished in particular by the mirror surface that reflects radiation at a wavelength of 13.5 nm.

[0042] Based on the post-processing method explained above, assuming all existing protrusions are removed, the MEMS chip and the carrier material supporting the MEMS structure are available only within the area of ​​the MEMS structure. Of course, it is also possible to at least partially avoid the corresponding protrusions during the fabrication of the MEMS chip, so that the number of protrusions to be removed by the above method can be reduced—possibly even reduced to zero.

[0043] In this regard, it is conceivable, for example, that when dividing a wafer of a MEMS structure on which multiple MEMS chips are applied, at least a portion of the cutting line is guided along the MEMS structure so that after the corresponding cut is made along the cutting line, no protruding area appears at least in a portion of the adjacent MEMS chip.

[0044] As an alternative, the carrier material of the wafer can be structured early in the MEMS structure manufacturing process. This allows for the introduction of continuous gaps into the carrier material and the direct division of the carrier material into individual MEMS chips in a later stage of the manufacturing process. In this case, at least the number of protruding areas can be reduced. It is even possible to manufacture MEMS chips without any protruding areas in this way.

[0045] Regardless of whether the protruding areas that may still exist are removed by the method according to the invention as described above, the availability of MEMS chips without any protruding areas—at the latest resulting—requires a change in the handling of MEMS chips compared to the prior art. Typically, corresponding protruding areas—as already mentioned—are needed for securing protective covers, which in the prior art are used for marking purposes—particularly as orientation and alignment aids for MEMS chips. Furthermore, protruding areas are often used as engagement points, for example, processed by tools. In the case of omitting protruding areas, especially due to the method according to the invention, alternative methods for handling MEMS chips are needed without protruding beyond the area of ​​the MEMS structure disposed on the carrier material.

[0046] Therefore, the present invention relates to a method for processing MEMS chips that do not protrude beyond the area of ​​a MEMS structure disposed on a carrier material. In this case, the corresponding MEMS chip may have already been created by post-processing according to the invention, although this is not necessary.

[0047] According to the invention, a corresponding “frameless” MEMS chip is processed by engaging a suitable tool in one or more lateral recesses in a carrier material. In this context, the term “lateral recess” refers to a recess at an end face of the carrier material. Thus, specifically, one side of the carrier material on which the MEMS structure is disposed, and the opposite side thereto, lack the aforementioned recesses, which are provided for engaging the tool for processing purposes.

[0048] Preferably, at least two lateral recesses are provided on two adjacent sides of the carrier material. The carrier material or MEMS chip can then be clamped and processed, leaving the other sides of the carrier material free. This allows for small gaps relative to adjacent MEMS chips during integration, as no gap between MEMS chips is needed where the processing tool would have to be guided between them. To avoid relative movement, particularly tilting, between the MEMS chip and the processing tool, three lateral recesses are preferably provided, with two of them located on the same side of the carrier material.

[0049] If the recesses are only provided on two adjacent sides of the carrier material, but at least one side of the carrier material is not recessed, the orientation of the MEMS structure of the MEMS chip relative to the carrier material can be read from the arrangement of the recesses, thus ensuring the correct alignment of the MEMS chip during the integration of the MEMS chip.

[0050] Alternatively or additionally, the markings can be arranged laterally on the carrier material. In addition to reference markings for proper orientation of the MEMS chip during integration, identifiers, such as those in the form of barcodes, can also be arranged laterally on the carrier material. The markings can also be configured as recesses or a set of recesses.

[0051] Lateral recesses and markings (if markings are set as recesses) for the bonding tool can be subsequently introduced after the MEMS chip production. However, a carrier material with sacrificial material can also be provided in the area set as a recess. In particular, the carrier material can be provided with an internal sacrificial material as early as the wafer state, and then the internal sacrificial material is exposed by separating the wafer into individual MEMS chips and subsequently removed.

[0052] As an alternative to processing MEMS chips by bonding them into lateral recesses in the carrier material, processing can also be achieved—depending on the configuration of the MEMS chip—by directly bonding them to the MEMS structure. If the MEMS chip is a mirror array, a suction plate with multiple suction openings corresponding to the number and arrangement of the individual mirrors can be used to create a fixed connection between each individual mirror in the mirror array and the suction plate. As a result, if the MEMS structure has sufficient load-bearing capacity, processing can be performed solely through bonding on the MEMS structure.

[0053] To process MEMS chips via bonding on the MEMS structure, electrostatic clamps, van der Waals clamps, vacuum clamps, Bernoulli clamps, and ultrasonic clamps can also be used. In the case of a Bernoulli clamp, the distance at which the gas flow is connected below it must be selected to ensure sufficient clamping force, and in the case of a MEMS mirror array as a MEMS chip, the vibration excitation of the mirrors is kept within acceptable limits due to the air flow. Attached Figure Description

[0054] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0055] Figure 1 A schematic diagram of a projection exposure apparatus for photolithography comprising the manufactured MEMS mirror array according to the present invention is shown.

[0056] Figure 2 ae illustrates a schematic diagram of a post-processing method for MEMS chips according to the present invention;

[0057] Figure 3 ad shows from Figure 2 A schematic diagram of possible structural variations of the separated region;

[0058] Figure 4 a and b show information about introducing high-energy radiation into... Figure 2 A schematic diagram of the separated regions;

[0059] Figure 5 ac shows that it is constructed from Figure 2 A schematic diagram of the separation of the separation region at the predetermined fracture location;

[0060] Figure 6 ac showed according to Figure 5 A schematic diagram of a tool used to separate a predetermined fracture location;

[0061] Figure 7 a and b show information about the basis Figure 2 A schematic diagram of the removal of sacrificial material in the separation region;

[0062] Figure 8 The diagram illustrates the fabrication of MEMS chips with and without protruding regions; and

[0063] Figure 9 a and b show schematic diagrams of processing MEMS chips without protruding areas. Detailed Implementation

[0064] Figure 1A schematic meridional section of a projection exposure apparatus 1 used for photolithography is shown. In this case, the projection exposure apparatus 1 includes an illumination system 10 and a projection system 20.

[0065] The object field 11 in the object plane or mask plane 12 is illuminated by means of an illumination system 10. For this purpose, the illumination system 10 includes an exposure radiation source 13, which, in the illustrated exemplary embodiment, emits illumination radiation comprising at least light used in the EUV range, specifically wavelengths between 5 nm and 30 nm. The exposure radiation source 13 can be a plasma source, such as an LPP (laser-generated plasma) source or a GDPP (gas discharge-generated plasma) source. It can also be a synchrotron-based radiation source. The exposure radiation source 13 can also be a free-electron laser (FEL).

[0066] The illumination radiation emitted from the exposure radiation source 13 is initially focused into the concentrator 14. The concentrator 14 may be a concentrator having one or more elliptical and / or hyperboloidal reflective surfaces. The illumination radiation may be incident on at least one reflective surface of the concentrator 14 at grazing incidence (GI) (i.e., at an angle of incidence greater than 45°) or normal incidence (NI) (i.e., at an angle of incidence less than 45°). The concentrator 14 may be structured and / or coated, on the one hand to optimize its reflectivity to the radiation used, and on the other hand to suppress intrusive light.

[0067] Downstream of the light collector 14, illumination radiation propagates through the intermediate focal point in the intermediate focal plane 15. If the illumination system 10 is constructed with a modular design, the intermediate focal plane 15 can, in principle, be used to separate (including structurally separate) the illumination system 10 into a radiation source module and an illumination optics unit 16, as described below, which includes an exposure radiation source 13 and a light collector 14. In the case of such separation, the radiation source module and the illumination optics unit 16 then together form the modularly constructed illumination system 10.

[0068] The illumination optics unit 16 includes a deflector 17. The deflector 17 may be a planar deflector, or alternatively a mirror having a beam-affecting effect beyond a pure deflection effect. Alternatively or additionally, the deflector 17 may be implemented as a spectral filter that separates the wavelength of the illumination radiation used from the intrusive light having wavelengths that deviate from it.

[0069] Deflector 17 is used to deflect radiation emitted from exposure radiation source 13 to first faceted mirror 18. If, in the present case, the first faceted mirror 18 is arranged in the plane of illumination optics unit 16 that is optically conjugate with mask plane 12 (as field plane), this faceted mirror is also called field faceted mirror.

[0070] The first faceted reflector 18 includes a plurality of micromirrors 18', each of which can be individually pivoted about two mutually perpendicular axes in each case for controllable terrain faceting. Each facet is preferably provided with an orientation sensor (not shown here) for determining the orientation of the micromirror 18'. Thus, the first faceted reflector 18 is a microelectromechanical system (MEMS system), as also described, for example, in DE 10 2008 009 600 A1.

[0071] The second faceted mirror 19 is arranged downstream of the first faceted mirror 18 in the beam path of the illumination optics unit 16, resulting in a double-faceted system, the basic principle of which is also called a fly-eye integrator. If the second faceted mirror 19 (as in the illustrated exemplary embodiment) is arranged in the pupil plane of the illumination optics unit 16, it is also called a pupil faceted mirror. However, the second faceted mirror 19 can also be arranged at a distance from the pupil plane of the illumination optics unit 16, thus creating a specular reflector by the combination of the first faceted mirror 18 and the second faceted mirror 19, as described, for example, in US 2006 / 0132747 A1, EP 1 614 008 B1, and US 6,573,978.

[0072] The second faceted mirror 19 does not necessarily need to be composed of pivotable micromirrors, but may comprise individual facets formed by a single mirror or a manageable number of mirrors significantly larger than the number of micromirrors, said facets being stationary or tiltable only between two defined end positions. However, as shown, it is also possible to provide a microelectromechanical system with multiple micromirrors 19' in the second faceted mirror 19, each of which can pivot individually about two mutually perpendicular axes, and each micromirror 19' preferably includes an orientation sensor.

[0073] Each facet of the first faceted mirror 18 is imaged into the object field 11 by means of the second faceted mirror 19, which is typically only an approximate image. The second faceted mirror 19 may be the final beam-shaping mirror or, in effect, the final mirror reflecting the illumination radiation in the beam path upstream of the object field 11.

[0074] In each case, one facet of the second faceted mirror 19 is assigned to exactly one facet of the first faceted mirror 18, with the aim of forming an illumination channel for illuminating the object field 11. This can in particular lead to illumination according to Köhler's principle.

[0075] For the purpose of illuminating the object field 11, the facets of the first faceted mirror 18 are imaged by overlapping the corresponding facets of the second faceted mirror 19. Here, the illumination of the object field 11 is as uniform as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by overlapping different illumination channels.

[0076] By selecting the final illumination channel, which can be properly set via the micromirrors 18' of the first faceted mirror 18, the intensity distribution in the entrance pupil of the projection system 20, as described below, can still be set. This intensity distribution is also referred to as the illumination setting. Incidentally, it may be advantageous here to arrange the second faceted mirror 19 imprecisely in a plane optically conjugate with the pupil plane of the projection system 20. In particular, the pupil faceted mirror 19 may be arranged tilted relative to the pupil plane of the projection system 20, for example, as described in DE 10 2017 220 586 A1.

[0077] However, in such Figure 1 In the arrangement of components of the illumination optical unit 16 shown, the second faceted mirror 19 is arranged in the region conjugate with the entrance pupil of the projection system 20. The deflecting mirror 17 and the two faceted mirrors 18, 19 are arranged at an angle relative to the object plane 12 and relative to each other in each case.

[0078] In an alternative embodiment (not shown) of the illumination optics unit 16, a transmission optics unit comprising one or more mirrors may be additionally provided in the beam path between the second faceted mirror 19 and the object field 11. The transmission optics unit may specifically comprise one or two normal incident mirrors (NI mirrors) and / or one or two grazing incident mirrors (GI mirrors). Using additional transmission optics units, in particular, allows for consideration of different orientations of the incident pupil for the tangential and sagittal beam paths of the projection system 20 described below.

[0079] Alternatively, Figure 1 The deflector 17 shown may be omitted; for this purpose, the faceted mirrors 18 and 19 should be appropriately arranged relative to the radiation source 13 and the light collector 14.

[0080] The object field 11 in the mask plane 12 is transferred to the image field 21 in the image plane 22 by means of the projection system 20.

[0081] For this purpose, the projection system 20 includes a plurality of mirrors Mi, which are sequentially numbered according to their arrangement in the beam path of the projection exposure device 1.

[0082] exist Figure 1 In the example shown, the projection system 20 includes six reflectors M1 to M6. It can also have four, eight, ten, twelve, or any other number of reflectors M1. iAlternatives are also possible. The penultimate reflector M5 and the last reflector M6 each have a channel opening for illumination radiation, thus the illustrated projection system 20 is a double-shielded optical unit. The projection system 20 has an image-side numerical aperture greater than 0.3, and the image-side numerical aperture can also be greater than 0.6, and can be, for example, 0.7 or 0.75.

[0083] Mirror M i The reflecting surface can be a free-form surface without a rotational axis of symmetry. However, the reflecting mirror M... i The reflective surface can also be alternatively designed as an aspherical surface with exactly one axis of rotational symmetry of its shape. Just like the reflector of the illumination optics unit 16, reflector M... i It can have a highly reflective coating for illumination radiation. These reflective coatings can be designed as multilayer coatings, especially with alternating layers of molybdenum and silicon.

[0084] The projection system 20 has a large object-image offset in the y-direction between the y-coordinate of the center of the object field 11 and the y-coordinate of the center of the image field 21. This object-image offset in the y-direction can have a magnitude approximately the same as the z-distance between the object plane 12 and the image plane 22.

[0085] In particular, the projection system 20 can be designed to be deformable, that is, it has different imaging scales β in the x and y directions. x β y The two imaging scales β of the projection system 20 x β y Preferably (β) x ,β y = (+ / -0.25, / +-0.125). An imaging scale β of 0.25 here corresponds to a reduction with a ratio of 4:1, while an imaging scale β of 0.125 results in a reduction with a ratio of 8:1. A positive sign in the case of imaging scale β means imaging without image inversion; a negative sign means imaging with image inversion.

[0086] Other imaging scales are also possible. Imaging scale β with the same sign and the same absolute value in both the x and y directions. x β y That's also possible.

[0087] The number of intermediate image planes in the x and y directions of the beam path between object field 11 and image field 21 may be the same or different, depending on the embodiment of 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 / 0074303A1.

[0088] Specifically, the projection system 20 may include concentric entrance pupils. These can be accessible, or they may be inaccessible.

[0089] A mask 30 (also referred to as a mask) arranged in the object field 11 is exposed by the illumination system 10 and transferred onto the image plane 21 by the projection system 20. The mask 30 is held by a mask holder 31. The mask holder 31 can be displaced, particularly in the scanning direction, by a mask displacement driver 32. In the exemplary embodiment shown, the scanning direction extends in the y-direction.

[0090] The structure on the mask 30 is imaged onto the photosensitive layer of the wafer 35, which is located in the image field 21 of the image plane 22. The wafer 35 is held by a wafer holder 36. The wafer holder 36 can be moved, particularly along the y-direction, by a wafer displacement driver 37. First, the mask 30 is moved by a mask displacement driver 32, and then the wafer 35 is moved by a wafer displacement driver 37, so that they are synchronized.

[0091] Figure 1 The projection exposure device 1 or its illumination system 10 shown (the above description reflects substantially known prior art) is characterized in that the first faceted mirror 18 and / or the second faceted mirror 19 contain one or more MEMS chips 100 for post-processing according to the present invention (see especially... Figure 2 Specifically, the MEMS mirror array 101. Each of the MEMS chips 100 here has a plurality of individual mirrors 103, which are independently adjustable in each case via two rotational degrees of freedom, as part of the MEMS structure 102, arranged in a two-dimensional grid. Each of the faceted mirrors 18, 19 may be formed by one or more MEMS chips 100 or MEMS mirror array 101 arranged adjacent to each other.

[0092] As is known, the corresponding MEMS mirror array 101 is co-produced on a common wafer with a plurality of other MEMS mirror arrays 100 or other MEMS chips 100 and is covered by an additional wafer with a suitable recess, such that when the wafer is subsequently divided into separate MEMS mirror arrays 101 or MEMS chips 100, a corresponding protective cover 106 for each individual MEMS mirror array 100 is maintained.

[0093] Figure 2A schematic cross-sectional view of two examples of MEMS chip 100 or MEMS mirror array 101, which in principle exist after the wafer has been diced. In the case of MEMS chip 100 or MEMS mirror array 101, the actual MEMS structure 102—i.e., the individual mirror 103 and all components required for system pivoting—is arranged on carrier material 104.

[0094] In this configuration, the carrier material 104 extends laterally beyond the area where the MEMS structure 102 is disposed, thus forming protruding regions 105 composed of protruding material. These protruding regions 105 are used to attach a protective cover 106 extending above the MEMS structure 102. The protective cover 106 can be fixedly attached to the protruding regions 105, for example, by means of an adhesive. Other bonding methods, such as, for example, anodizing, can also be used to attach the protective cover 106 to the protruding regions 105.

[0095] exist Figure 2 In the embodiment variant shown on the left in diagram a, a separation region 200 has been formed between the carrier material 104 and the protruding region 105 in the region where the MEMS structure 102 is disposed. This separation region will be combined below. Figure 3 To explain even in more detail. In Figure 2 In the embodiment variant shown on the right in b, the corresponding separation region 200 has not yet been provided.

[0096] Figure 2 Similarly, a packaging substrate 150 is shown, on which the MEMS chip 100 or MEMS mirror array 101 is intended to be arranged or disposed. In this case, the extent of the packaging substrate 150 can be adapted to the extent of the region of the carrier material 104 where the MEMS structure 102 is disposed. However, the packaging substrate 150 may also be significantly larger than the region in question, which is composed of... Figure 2 The dashed line portion of the packaging substrate 150 is indicated in the image.

[0097] even though Figure 2 It is shown that, in principle, the method according to the present invention can also be performed without providing the packaging substrate 150, i.e., using only the actual MEMS chip 100. In this case, it should be skipped. Figure 2 The steps shown in b are correct, and the packaging substrate 150 should be ignored in each subsequent figure.

[0098] Specifically, Figure 2Example b illustrates that the MEMS chip 100 or the MEMS mirror array 101 is fixedly connected to the package substrate 150. If the package substrate 150 extends beyond the region of the carrier material 104 where the MEMS structure 102 is provided, the protruding region 105 and the optional separation region 200 should (if possible) not be connected to the package substrate 150.

[0099] In the next step, the protective cover 106 can be optionally removed, which is why it is shown only in dashed lines in Figure 2 c. The protective cover 106 can be removed by releasing the adhesive connection between the protective cover 106 and the protruding region 105. If the adhesive used is a thermally decomposable adhesive, for example, the temperature can be appropriately increased at least locally. Of course, other separation methods are also possible. The fact of whether the protective cover 106 actually needs to be removed depends decisively on the configuration of the separation region 200 that already exists ( Figure 2 c, left side) or the separation region 200 to be created subsequently ( Figure 2 c, right side). Particularly relevant here is whether the separation region 200 needs to be accessible from the region covered by the protective cover 106, which is typically especially the case for the arrangements already implemented on the package substrate 150; if the package substrate 150 does not (yet) exist, then the separation region 200 can be accessed from the side of the carrier material 104 facing away from the MEMS structure 102, and thus it may not be necessary to remove the protective cover 106 in the steps described in Figure 2 c.

[0100] If the separation region 200 has not yet been formed ( Figure 2 c, right side), then this must be done in the next step ( Figure 2 d, right side). The possibilities regarding the configuration of the separation region 200 will be described in more detail in connection with Figure 3 below.

[0101] Finally, the protruding region 105 is separated and removed at the separation region 200 ( Figure 2 e). If the protective cover 106 is still fixedly connected to the protruding region 105, the protruding region 105 and the protective cover 106 can be removed as a unit. Some possible methods for actually removing the protruding region 105 and the protective cover 106 will be discussed in connection with Figures 5 to 7 below.

[0102] If the MEMS chip 100 has not been previously arranged on the package substrate 150, the MEMS chip 100 can be arranged on the package substrate at the latest at this time point, which will be further illustrated in connection with Figure 9 below.

[0103] Figure 3Various constructions of the separation region 200 or methods for separating protruding material in the protruding region 105 are schematically depicted.

[0104] exist Figure 3 In a, the separation region 200 is in the initial state ( Figure 3 a, on the left) is not specially configured. Instead, the carrier material 104 extends beyond the separation region 200 into the protrusion region 105. To separate the protrusion region 105, a continuous gap 201 is created between the protrusion region 105 of the MEMS chip 100 and the carrier material 104 by removing the material that was initially located there without leaving any residue. Figure 3 a, right side). In this case, removal can be achieved specifically through high-energy radiation, such as, for example, ionizing radiation or laser radiation. (See below for reference.) Figure 4 Possible variations of embodiments for this purpose are described.

[0105] High-energy radiation can be applied to the separation region 200 from the side of the carrier material 104 where the MEMS structure 102 is disposed and / or from the side opposite to it. Once the continuous gap 201 has been completed, the protruding region 105 and the protective cap 106, which may still be attached thereto, have been directly separated from the carrier material 104 and can be removed directly.

[0106] Figure 3 b illustrates an alternative procedure for creating a continuous gap 201 between the carrier material 104 and the protruding region 105. Here, in the initial state ( Figure 3 In b, left side), a sacrificial material 202 is provided in the separation region 200, which is different from the carrier material 104 and the protruding material in the protruding region 105. The sacrificial material 202 may be introduced into the carrier material 104, particularly during the production of the MEMS structure 102, or may have already been introduced at that point in time.

[0107] To create the continuous gap 201, only the sacrificial material 202 needs to be removed. In this case, the sacrificial material 202 can be removed specifically by means of an etching process, wherein appropriate selection of the sacrificial material 202 and the etchant ensures that neither the carrier material nor the MEMS structure 102 is damaged. Alternatively, the sacrificial material 202 can be thermally decomposable, and the continuous gap 201 is created by at least sufficient heating of the sacrificial material 202. Needless to say, the sacrificial material 202 can also be removed by means of suitable high-energy radiation.

[0108] After the sacrificial material 202 has been completely removed, a continuous gap 201 has been created, so the protruding area 105 and the protective cover 106, which may still be attached thereto, have been directly separated from the carrier material 104. The protruding area 105 and / or the protective cover 106 can then be removed directly.

[0109] According to Figure 3 In the embodiment variant of c, no continuous gap 201 is generated (see Figure 3 Instead of (a, b), a predetermined fracture location 203 is created, wherein the material in the separation region 200 is reduced to a thin and easily fractured material bridge 204. The location of the material bridge 204 and the remaining portion within the separation region 200 can be selected as needed, wherein, as in Figure 3 As exemplarily shown in the middle of c, the position relative to the edge of the carrier material 104 is advantageous because creating it requires processing the MEMS chip 100 on only one side.

[0110] To generate the predetermined fracture location 203, a bonding method can be used. Figure 3 a and Figure 3 The process described in b, specifically, removes material from separation region 200 without residue by high-energy radiation or by removing sacrificial material 202 that has been pre-introduced into separation region 200. For explanation of these processes, refer to the statements above. Essentially, the material bridge 204 is retained according to... Figure 3 In the embodiment variant of c.

[0111] After the predetermined fracture point 203 has been established, the protruding area 105 and the protective cap 106, which may still be attached thereto, can be released from the carrier material 104 by breaking the predetermined fracture point 203 and can subsequently be removed. See also... Figures 5 to 7 To illustrate the variation that causes the predetermined fracture location 203 to fracture.

[0112] Figure 3 d illustrates a further alternative for generating the predetermined fracture location 203. Starting from the separation region 200, the carrier material 104 extends to the right beyond the separation region 200 into the protruding region 105. Figure 3 (d, left side), the material in the region where the predetermined fracture location 203 is to be generated is weakened in a targeted manner. This is due to... Figure 3 The weakened region 205 in the middle is shown. In this respect, for example by means of suitable radiation, the crystal structure of the carrier material 104 in the weakened region 205 can be disrupted, i.e., transformed from a single crystal and / or polycrystalline structure to an amorphous structure. Furthermore, local heating can lead to a decrease in density in the weakened region 205, and thus result in the weakening of the material.

[0113] After the weakening has been achieved, the predetermined fracture location 203 can be broken, so that the protruding area 105 and the protective cover 106 that may still be attached to it can be separated from the carrier material 104 and removed.

[0114] Refer to the above Figure 3In all the processes described in the use of high-energy radiation to generate the continuous gap 201 or the predetermined fracture location 203, it should be noted that the corresponding radiation 300 (see...) Figure 4 a) Even when strongly focused, it has a numerical aperture (though typically very small) that may impede radiation, particularly on the sides of the carrier material 104 on which the MEMS structure 102 is disposed. Due to the numerical aperture—at least if the incident angle of the radiation is fixed at 0°, although this is usually the case—it is practically impossible to create a continuous gap 201 or a predetermined break point 203 directly adjacent to the area of ​​the carrier material 104 on which the MEMS structure 102 is actually disposed during irradiation of the sides of the carrier material 104 on which the MEMS structure 102 is disposed. In the corresponding procedure, the MEMS structure 102 is practically inevitably struck by the focused radiation 300 and adversely affected.

[0115] However, as an alternative, such as Figure 4 As schematically shown in b, a collimated beam 301 (i.e., a beam with only parallel rays) can be used, which is confined to the separation region 200 by a suitable shielding mask 302. In this case, the radiation impacting the separation region 200 has an incident angle of 0°, so that even during irradiation of the side of the carrier material 104 where the MEMS structure 102 is disposed, material directly adjacent to the region of the carrier material 104 where the MEMS structure 102 is disposed can be removed without residue.

[0116] If a predetermined fracture location 203 has already been formed in the separation region 200 (see...) Figure 3 (c, d), then Figure 5 Three possible ways in which the predetermined fracture location 203 is fractured are schematically illustrated. In this case, in principle, the predetermined fracture location 203 has already been created or formed in any desired manner.

[0117] according to Figure 5 a. The predetermined fracture location 203 is separated by shear stress introduced at the predetermined fracture location 203. This shear stress can be obtained by applying opposing forces to the carrier material 104 and the protruding region 105. This is achieved by... Figure 5 Arrow 90 in a indicates that the orientation of arrow 90 can also be reversed.

[0118] As an alternative, such as Figure 5 The predetermined fracture location 203, schematically depicted in a, can also fracture by applying sufficient tensile stress to it, as indicated by arrow 91.

[0119] When according to Figure 5When a fracture occurs at the predetermined fracture location 203, it is particularly relevant to a variant of the embodiment where the material in the separation region 200 is partially weakened (see [reference]). Figure 3 d) A temperature or temperature gradient is introduced at the predetermined fracture location 203 (represented by the heating element 92, although a cooling facility may also be provided). For example, the different thermal expansion of the weakened region 205 relative to the unmodified material may cause fracture at the predetermined fracture location.

[0120] Figure 6 It shows how to make the already referenced Figure 5 Various variations or tools 400 that introduce shear stress at the predetermined fracture location 203, as mentioned in a.

[0121] exist Figure 6 In case a, it is assumed that the protective cover 106 remains fixedly connected to the protruding area 105, however, for parts of it—unlike the carrier material 104 in the area with MEMS structure 102—it is not connected to the encapsulation substrate 150.

[0122] In this configuration, the tool 400 used to break the predetermined fracture location 203 is a suction mold 401, which is fixedly connected to the protective cover 106 by creating a vacuum between the suction mold 401 and the protective cover. By pulling the suction mold 401 in a direction away from the packaging substrate 150 while simultaneously fixing the suction mold 401, shear stress is generated at the predetermined fracture location 203, and this shear stress can cause it to fracture. Therefore, the protective cover 106 and the protruding area 105 fixedly connected thereto can be removed from the MEMS chip 100 through the suction mold 401. As an alternative to the suction mold 401, a similar tool 400 can also be fixedly connected to the protective cover 106 by adhesive bonding.

[0123] Figure 6 Tool 400 in b is particularly suitable for applications where the MEMS chip 100 is disposed on a packaging substrate 150, which does not extend beyond the area of ​​the carrier material 104 where the MEMS structure 102 is disposed. Tool 400 is a movable clamp 402, such as Figure 6 As shown in b, the movable clamp 402 is positioned adjacent to the encapsulation substrate 150. By means of the vertical movement of the clamp 402, while the encapsulation substrate 150 remains fixed, a predetermined fracture point 203 can be broken. The protruding area 105 abutting against the clamp 402 is connected to the carrier material 104 via this predetermined fracture point 203, and the separated material can be removed. In this case, whether the protective cover 106 is connected to the protruding area 105 at the time of fracture is irrelevant.

[0124] exist Figure 6 In c, use from Figure 6Tool 400, although clamp 402 is positioned above protruding region 105 in such a manner that vertical movement of clamp 402 in the direction of encapsulation substrate 150 causes protruding region 105 to break accordingly in the direction of encapsulation substrate 150 at the corresponding predetermined break location 203. Advantageously, with respect to this embodiment variant, there is no risk of collision between the separated material and MEMS structure 102. However, in this embodiment variant, it is absolutely necessary to remove any protective cap 106 that may be present before the first predetermined break location 203 breaks.

[0125] If the sacrificial material 202 is placed in the separation region 200 (see...) Figure 3 (b, c) In order to create the continuous gap 201 or the predetermined fracture location 203, the sacrificial material must be removed, which can be done, for example, by using an etching process with an etching medium, such as using an etching gas.

[0126] To minimize the volume of the etching medium to be loaded and to protect areas away from the MEMS chip 100 from its effects, inlet and outlet channels 107 can be introduced, or, as needed, these channels can be introduced into the protective cover 106, which still exists at that point in time. Through these channels, etching medium suitable for dissolving the sacrificial material 202 in the separation region 200 can be introduced, and the used etching medium can also be removed again (see...). Figure 7 a). After the sacrificial material 202 has been removed, the separation of the protective cover 106 and the protruding area 105 connected thereto—whether resulting in a continuous gap 201 or a predetermined break point 203—can then, for example, be based on Figure 6 a occurs.

[0127] Figure 7 Figure b illustrates a variation in which the MEMS chip 100, with or without the protective cap 106 (thus shown only in dashed lines), is housed in a separate etching chamber 450, which, together with a possible encapsulation substrate 150, surrounds the MEMS chip 100, or—as shown—sealed against the encapsulation substrate 150 and introduces the etching medium through its inlet and outlet 451. In particular, this method can also remove sacrificial material 202 accessible only from the side opposite to the MEMS structure 102 in the separation region 200. Optionally, the final removal of the protruding region 105 and / or the protective cap 106 may include a predetermined fracture location resulting from the destruction, as explained above.

[0128] Even if the protruding region 105 can be removed by the above-described method for post-processing of MEMS chip 100, the protruding region 105 can be reduced or even completely avoided as early as during the manufacturing of the corresponding MEMS chip 100, and thus the expenditure for the corresponding post-processing can be reduced or completely avoided.

[0129] Figure 8 A schematic depiction illustrates a typical manufacturing process for a MEMS chip 100: multiple sets of MEMS structures 102 are created on a wafer 500, each set later forming a separate MEMS chip 100. Figure 8 a, left side). Corresponding gaps 501 are provided between the groups of MEMS structures 102, and as known from the prior art, the corresponding gaps 501 can be used, for example, to connect a wafer with a recess (not shown) to the illustrated wafer 500, so that a protective cover 106 can be formed for the MEMS chip 100 after the wafer 500 is separated centered through the gaps. Figure 8 The right side of a shows the situation after the wafer 500 has been divided in this manner. After the wafer 500 is separated, each MEMS chip 100 has a surrounding protruding area 105, and in particular, a separate protective cover 106 can be fixed to the protruding area 105 (see Figure 105). Figure 2 ).

[0130] To facilitate the removal of the protruding region 105, when the wafer 500 is being split or at a later point in time, the protruding region 105 can be subdivided into individual segments by creating gaps or weakening the region 502, and these segments can in principle also be removed individually.

[0131] In particular, if the protective cover 106 is not required during further processing of the MEMS chip 100, the MEMS structures 102 can be arranged in pairs adjacent to each other in one direction on the wafer 500 in each case. Figure 8 b, on the left). After the wafer 500 is split, this then results in a separate MEMS chip 100, in which the protruding region 105 no longer exists circumferentially (see...). Figure 8 a, right side), but only on two of the four sides of each MEMS chip 100 (a, right side), Figure 8 (b, right side). The expenditure for post-processing (i.e., for removing residual protruding areas 105) is correspondingly reduced. Here, the protruding areas 105 can also be appropriately subdivided into segments that can be removed individually.

[0132] As an alternative, it is also possible to use chip 500 (see...) Figure 8 There is absolutely no gap on c, left side) 501 (see ... Figure 8The MEMS structure 102 is arranged in a and b) such that the segmented wafer 500 directly generates a region 105 without any protruding areas. Figure 8 c, the MEMS chip 100 (right side). In this case, the wafer 500 can be divided using any known process. In particular, division can also be performed by appropriately removing the carrier material during the fabrication of the MEMS structure. In this case, a process known from the production of MEMS structures for selectively removing material—such as an etching process—can be directly applied to the carrier material to achieve division. This etching process can be provided as a separate step in the production process of the MEMS structure. However, "accompanying removal" can also be implemented in the method steps for producing the MEMS structure.

[0133] If the MEMS chip 100 without any protruding areas 105 is usable—regardless of whether they have been released from the originally present protruding areas 105 by the post-processing method according to the invention (see...) Figures 2 to 7 ) or it has been manufactured without a prominent area 105 (see Figure 8 c) — If this is not already done, they can be arranged at a very small distance from each other on the packaging substrate 150, such as Figure 9 a is illustrated schematically.

[0134] To process the MEMS chip 100, a tool 600 is provided, which enables the individual MEMS chip 100 to be gripped on two adjacent sides of the carrier material 104, such that the MEMS chip 100 can be arranged such that the other two sides of the carrier material 104 are directly adjacent to the MEMS chip 100 already disposed on the packaging substrate 150. Figure 9 Figure b illustrates the tool 600 and its interaction with the MEMS chip 100 in two plan views and two associated partial sectional views, with the right-hand views showing the tool 600 in engagement and the left-hand views showing the tool 600 still detached from the MEMS chip 100.

[0135] In order for the MEMS chip 100 to be firmly and precisely clamped by the tool 600, the MEMS chip 100 has a lateral recess 108 in the region of the carrier material 104, and a corresponding protrusion 601 on the tool 600 can be engaged into the recess in a shape-locking manner, the protrusion 601 being configured like pliers for the rest of the portion.

[0136] In addition to the two recesses 108, the orientation of the MEMS chip’s MEMS structure relative to the carrier material can also be read from them.

[0137] If recesses for the bonding processing tool 600 are provided only on two adjacent sides of the carrier material, but at least one side of the carrier material is without recesses, the orientation of the MEMS structure 102 of the MEMS chip 100 relative to the carrier material 104 can be read from the arrangement of the recesses, thus ensuring proper alignment of each MEMS chip 100 during integration. Further recesses, in a form and arrangement equivalent to barcodes, can be provided on the carrier material 100 as markings 109, storing the batch number or serial number of the corresponding MEMS chip 100.

[0138] The recess 108 and the marker 109 can be integrated into the carrier material 104 during the production of the MEMS chip 100. Specifically, the region in question, which is at least temporarily the regular interior region, can be filled first with sacrificial material corresponding to the sacrificial material 202 in the separation region 200, and the material can be removed during the removal of the sacrificial material 202 in the separation region 200.

Claims

1. A method for post-processing of a MEMS chip (100) comprising a MEMS structure (102) arranged on a carrier material (104), wherein at least one protruding region (105) of a protruding material laterally protrudes beyond the region of the MEMS chip (100) provided with the MEMS structure (102), characterized in that at least one protruding region (105) is removed by separating the protruding material from the carrier material (104) of the MEMS chip.

2. The method according to claim 1, characterized in that at least one protruding region (105) is removed by creating a continuous gap (201) between the carrier material (104) and the protruding region (105) of the MEMS chip (100).

3. The method according to any of the preceding claims, characterized in that at least one protruding region (105) is removed by creating a predetermined breaking location (203) between the carrier material (104) and the protruding region (105) of the MEMS chip (100) and subsequently breaking the predetermined breaking location (203).

4. The method according to claim 2 or 3, characterized in that for creating the continuous gap (201) and / or the predetermined breaking location, a sacrificial material (202) arranged in this region and different from the protruding material is removed.

5. The method according to claim 4, characterized in that the sacrificial material (202) is removed by an etching process.

6. The method according to claim 2 or 3, characterized in that for creating the continuous gap (201) and / or the predetermined breaking location (203), material is removed, preferably by high-energy radiation, without residues.

7. The method according to claim 3, characterized in that for creating the predetermined breaking location (203), the material in the region of the predetermined breaking location (203) to be created is weakened in a targeted manner, preferably by high-energy radiation.

8. The method according to claim 6 or 7, characterized in that a shadow mask (302) is used for beam shaping of the high-energy radiation.

9. The method according to any of claims 3 to 8, characterized in that the created predetermined breaking location (203) is broken by introducing shear stresses (90) and / or tensile stresses (91).

10. The method according to any of claims 3 to 8, characterized in that the created predetermined breaking location (203) is broken by changing the temperature and / or by introducing a temperature gradient.

11. The method according to any of the preceding claims, characterized in that at least one protruding region (105) is configured for attaching a protective cover (106) for the MEMS chip (100), and the protective cover (106) is removed, preferably simultaneously with the protruding region (105).

12. The method according to any of the preceding claims, characterized in that The MEMS chip (100) is a MEMS mirror array (101), preferably for lithography, more preferably for EUV lithography.

13. A method for processing a MEMS chip (100) without having protrusions beyond the area (105) of the MEMS structure (102) arranged on a carrier material (104), in particular after the post-processing according to any one of claims 1 to 12, characterized in that at least one lateral recess (108) is provided in the carrier material (104) and the MEMS chip (100) is processed by a tool (600) engaged in the lateral recess.

14. The method according to claim 13, characterized in that at least two lateral recesses (108) are provided on two mutually adjacent sides of the carrier material (104).

15. The method according to claim 13 or 14, characterized in that a marking (109) is arranged laterally on the carrier material (104).

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