Method for producing and handling MEMS chips

Abstract

The invention relates to a method for producing and handling MEMS chips (120) having MEMS structures (122) extending substantially over the entire top surface thereof. In the method, at least the following method steps are carried out: A pre-structured wafer (100) having a number of pre-structured MEMS chips (120) is provided. A substantially circumferential tongue-and-groove structure (150, 152) is formed in the pre-structured wafer (100), between an outer contour of a component, in particular an MEMS chip (120), and a complementary inner contour of a frame structure (206, 208-214) or parts (100') of the wafer (100). At least one protective wafer (198) is then applied to one side of the wafer (100) by means of a temporary joining process. MEMS chips (120) from the pre-structured wafer (100) are exposed by means of an etching process at filled etching structures (105). The exposed MEMS chips (120) are retained within a cage (202) of the pre-structured wafer (100). The exposed MEMS chips (120) retained in the wafer (100) are removed therefrom by means of a vertical extraction process (226), which takes place after a local expansion process (192) has been carried out. The invention also relates to the use of the method to produce and handle MEMS chips (120).

Description

[0001] Description

[0002] title

[0003] Methods for manufacturing and handling MEMS chips

[0004] Technical area

[0005] The invention relates to a method for producing and handling MEMS chips with MEMS structures extending substantially over their entire surface. Furthermore, the invention relates to the use of the method for producing and handling MEMS chips.

[0006] State of the art

[0007] WO 2017 / 129171 A1 discloses a method and apparatus for separating a microchip from a wafer and applying the microchip to a substrate. During the detachment process, the microchip is snapped onto the free end of a tip. It adheres to the tip by adhesive force during transport to the substrate. Until the microchip is detachable, it is held in place by webs known as retaining tabs. These webs, which serve as retaining tabs, are broken during detachment.

[0008] DE 10 2018 214 017 A1 relates to the production of a thin film with a microsystem, wherein the microsystem is produced on the thin film and peeled off together with the thin film. Among other things, it is proposed to form webs between an outer region and an inner region of the thin film, wherein the microsystem is located on the inner region of the thin film. When the inner region is peeled off, the webs can break. A support structure can be formed which extends over the inner region and at least partially over the webs and which is peeled off together with the inner region. It is further disclosed to design the webs with tapered regions in order to define predetermined breaking points. US 2008 / 0044985 A1 discloses the use of sacrificial support parts on workpieces with microfeatures such as semiconductor wafers, wherein the workpiece comprises a substrate and microelectrical dies.Furthermore, the workpiece has a sacrificial support part, which is attached over the die and serves for protection and transport. It is disclosed to perform a singulation of such a workpiece, wherein the singulation also relates to the sacrificial support part. A singulated die is applied to a carrier substrate, for example, an interposer substrate, using the corresponding part of the sacrificial support part. The sacrificial support part is subsequently removed. Using such an approach, a device with microfeatures, for example, a microelectronic or micromechanical device, can be produced.

[0009] WO 2017 / 129171 A1 and DE 10 2018 214 017 A1 describe various possibilities for singulating wafers and then transporting the singulated chips. The use of webs is disclosed, with DE 10 2018 214 017 A1 also proposing the use of specially shaped webs with tapered sections.

[0010] US 2008 / 0044985 A1 discloses the general idea of ​​using special elements for transporting chips and their subsequent removal.

[0011] DE 10 2015 206 996 A1 relates to a method for producing microelectromechanical structures in a layer sequence and a corresponding electronic component with a microelectromechanical structure. A method for producing microelectromechanical structures in a layer sequence is proposed, wherein a carrier substrate having a first surface is first provided. An insulating layer is applied to the first surface of the carrier substrate. This is followed by epitaxial growth of a first silicon layer onto the insulating layer, after which the first silicon layer is structured to form trenches in the first silicon layer, wherein the trenches extend at least partially through the first silicon layer.The first silicon layer is then passivated, filling the trenches and forming a passivation layer on a side facing away from the first surface. The passivation layer is patterned, forming sacrificial regions and functional regions in the first silicon layer, and the sacrificial regions on a side facing away from the carrier substrate are at least partially free of the passivation layer. The sacrificial regions are then removed.

[0012] For MEMS components, which have sensitive, movable elements, such as mirror elements, located across the entire surface, especially on the front of the component, the separation and subsequent handling of the components for further processing is difficult. Handling of the separated component can only be achieved contactlessly, from the back, the side, or on additional auxiliary surfaces that serve no other function.

[0013] The use of contactless handling techniques, such as Bernoulli handling or acoustic levitation, is often impossible due to the very weak coupling to the component. Such techniques also have the disadvantage that the moving, sensitive MEMS structures can be damaged by the gas flow during Bernoulli handling or by the acoustic vibrations themselves during acoustic levitation. Acoustic levitation also has limitations due to the influence of the geometry of the immediate environment on the required sound field.

[0014] Handling from the back is generally not possible when assembling a component onto a substrate, for example when soldering it on.

[0015] If auxiliary surfaces are provided outside the MEMS structures for attaching protective caps and for handling, this reduces the achievable (optical) fill factor. Without such a frame, the individual components for assembly in an array can only be handled on two of the six chip side surfaces.

[0016] Disclosure of the invention

[0017] A method is proposed for the production and handling of MEMS chips with MEMS structures extending substantially over their entire surface, wherein at least the following method steps are carried out: a) Providing a pre-structured wafer with a number of pre-structured MEMS chips, b) Forming a substantially circumferential tongue and groove structure in the pre-structured wafer between an outer contour of a component, in particular a MEMS chip, and a complementary inner contour of a frame structure or parts of the wafer, c) Applying at least one protective wafer to one side of the wafer by means of a temporary joining process, d) Isolating a MEMS chip from the pre-structured wafer by means of an etching process of filled etching structures,e) holding released MEMS chips within a cage in the pre-structured wafer and f) vertically removing the MEMS chips obtained according to process step e) from the pre-structured wafer after a local expansion.

[0018] The method proposed according to the invention ensures that, in particular, the touch-sensitive surfaces of the essentially full-surface MEMS structures, for example in micromirror arrangements and micromirror arrays, remain contact-free and are protected from damage. Furthermore, the method proposed according to the invention enables, in particular, the production of a MEMS array with a very high optical fill factor.

[0019] In an advantageous embodiment of the method proposed by the invention, the pre-structured wafers are produced using a single-layer structure. This enables the formation of various individual layers on the MEMS chip and its surroundings, particularly thanks to the circumferential tongue and groove structure.

[0020] In an advantageous embodiment of the method proposed according to the invention, the pre-structured wafer is provided with at least one protective wafer on its front side by means of temporary bonding by forming a bond connection. The at least one protective wafer, which has a cavity facing the front side of the wafer, can, in particular, protect the MEMS structures present on the surface of the MEMS chip and extending over the entire surface from damage. The method proposed according to the invention advantageously provides for the removal of filled etched structures between the inner and outer contours of the essentially circumferential tongue and groove structure during a release according to method step c).

[0021] Advantageously, the method proposed according to the invention provides that, according to method step d), the release step, exposed sacrificial layers, in particular silicon and / or silicon oxide, are dissolved out by means of an etching process in SFe or XeF2, or oxide sacrificial layers are removed by HF gas-phase etching. The sacrificial layers are preferably made of silicon oxide or silicon oxide with silicon. By removing the exposed sacrificial layers, a cage is obtained in which the MEMS chip, now present after carrying out method step d), is held, but without being firmly connected to the surrounding silicon material of the pre-structured silicon wafer.

[0022] In an advantageous development of the method proposed according to the invention, after performing method step c), the MEMS chip is laterally movable within the cage and is held in exposed etched structures, tongue and groove structures forming the inner and outer contours. Within the cage, the lateral mobility of the MEMS chips is as small as possible. The lateral freedom of movement of the MEMS chips is on the order of the thickness of the previously removed sacrificial layers. The smaller the lateral freedom of movement of the MEMS chips, the greater the accuracy that can be achieved in subsequent process steps due to corresponding positioning tolerances.

[0023] In an advantageous development of the method proposed according to the invention, after performing process step d), the wafer is laminated on its back side to an expandable substrate. The expandable substrate can, for example, be a band or tape that can be expanded in all directions, or something similar.

[0024] In a further development of the method proposed according to the invention, it is proposed that, according to method step d), the expandable base performs an expansion movement laterally, radially, or in an X and Y direction, during which the tongue and groove structure is disengaged. This frees the MEMS chip, which previously performed lateral movements within the cage within the wafer structure, and allows it to be handled.

[0025] Advantageously, the method proposed according to the invention provides that the at least one protective wafer is provided with a cavity and at least one trench-shaped weakening zone on its rear side facing the front side of the wafer. This allows predetermined breaking points to be defined in the protective wafer, at which the protective wafer can be separated.

[0026] Advantageously, the method proposed according to the invention provides that the at least one trench-shaped weakening zone and the cavity are produced by means of an etching process.

[0027] In a further development of the method proposed according to the invention, a decreasing slot width is set by means of a depth of the at least one trench-shaped weakening zone, and / or the depth of the at least one trench-shaped weakening zone is set such that dividing lines are defined in the at least one protective wafer upon execution of a lateral expansion movement. The geometry of the trench-shaped weakening zones thus makes it possible to achieve a defined separation of the protective wafer protecting the MEMS structures on the top side of the wafer.

[0028] In an advantageous development of the method proposed according to the invention, a membrane of the protective wafer is formed on at least one side of the cavity free of weakening zones in such a way that it remains connected during the lateral expansion movement. This ensures that during the separation movement, due to the lateral expansion, contact between parts of the protective wafer and the sensitive upper side of the MEMS chip or the MEMS structures running across the entire surface there is prevented. After the expansion of the expandable base, a part of the protective wafer which lies above the MEMS structure can touch it. To prevent this, a sufficient safety distance can be maintained with respect to the MEMS structures by positioning the weakening zones, i.e. the trench-shaped slits, which reliably rules out a collision.In the method proposed according to the invention, parts of the wafer are separated laterally and the at least one protective wafer is separated along the at least one separating line during the lateral expansion movement.

[0029] In the method proposed according to the invention, frame elements of a frame structure within the wafer composite can be separated during the lateral expansion movement.

[0030] In an advantageous development of the method proposed according to the invention, the separated frame elements and the wafer parts attached to them are removed from the expandable support, in particular by vertical removal. A pick-and-place tool or another fully automated handling device is advantageously suitable for this purpose.

[0031] In the method proposed by the invention, at least one temporary bond connection is formed in the form of a bond frame, through which the front side of the wafer and the at least one protective wafer can be provided to protect the touch-sensitive MEMS structures. Alternatively, it is possible to attach the protective wafers without a temporary bond connection.

[0032] In a further development of the method proposed by the invention, the at least one trench-shaped weakening zone in the at least one protective wafer has profiles that are either parallel to one another or crossed with respect to one another. This allows the dividing lines within the protective wafer to be determined based on the defined position of the at least one trench-shaped weakening zone.

[0033] In the method proposed by the invention, according to a further aspect of the present invention, during the release of the MEMS chips during the implementation of method step d), handling surfaces can remain in the material of the wafer, which can preferably be a pre-structured silicon wafer. These handling surfaces can be formed essentially in an L-shape, having a first leg and a second leg running at right angles to the first leg. By means of these handling surfaces created during the release of the MEMS chips, the MEMS chips, which are connected, for example, via bridge webs, can be handled after release using a pick-and-place tool or similar and placed within an MEMS array.

[0034] In an advantageous development of the method proposed according to the invention, during the release of the MEMS chips according to method step d) in the material of the wafer, which can in particular be a pre-structured silicon wafer, the tongue and groove structures are also released with the production of said handling surfaces.

[0035] In the method proposed according to the invention, electronic components, in particular ASICs or the like, can be placed on the back of the wafer and the handling surfaces and / or handling surfaces of adjacent MEMS chips can be provided with replacement layers whose thickness substantially corresponds to a thickness of the electronic components, which can in particular be designed as ASICs. By applying the replacement layers to the parts of the wafer arrangement not placed with electronic components in the form of ASICs, a uniform processing surface can be achieved, which makes handling considerably easier. The replacement layers also enable the protective wafer to be separated by expanding the wafer in the lateral expansion direction on the expandable base.

[0036] In the method proposed by the invention, according to a further, third aspect of the present invention, the handling surfaces can also be formed by protruding edges of the electronic components, in particular designed as ASICs, which are placed on the backside of the MEMS chips in the wafer. These protruding edges correspond to the aforementioned handling surfaces, which can be formed in the wafer material during the release according to method step c).

[0037] In an advantageous further development of this embodiment of the method proposed according to the invention, a stepped edge structure is created in the cross-section of the MEMS chips by the protruding edges of the electronic components, in particular ASICs, on the one hand, and an edge of the MEMS chips on the other. In an advantageous further development of this embodiment of the method proposed according to the invention, said protruding edges are formed on two adjacent sides of the MEMS chips by the protruding edges of the electronic components, in particular designed as ASICs, so that an L-shaped pattern of the protruding edges of the electronic components, in particular designed as ASICs, is obtained.

[0038] In this embodiment of the method proposed according to the invention, a complementary step-shaped edge structure is formed on the sides of the MEMS chip opposite the two adjacent sides

[0039] In this embodiment of the method proposed according to the invention, the projecting edges serve as a handling surface, alternatively to the above-mentioned handling surfaces, which can be manufactured from the material of the wafer, which is designed in particular as a pre-structured silicon wafer, during the release step according to method step d).

[0040] Furthermore, the invention relates to the use of the method for producing and handling MEMS chips and their arrangement in a MEMS array with a high optical fill factor.

[0041] Advantages of the invention

[0042] According to a first aspect of the solution proposed by the invention, a separation method for MEMS chips with full-surface, movable, or sensitive MEMS structures is presented. The separation of individual MEMS chips from a wafer assembly using the method proposed by the invention does not require the separation of fixed connections, such as the separation of connecting bridges using a laser application or mechanical removal (pick and crack).

[0043] In contrast to previous solutions, unlike sawing, grinding, or separating using diamond blades, no wet-chemical additives, such as water for cooling, are required for removing the MEMS chips from the wafer assembly. According to the first aspect of the solution proposed by the invention, a circumferential tongue and groove structure is formed on the outer contour of the individual components. One structure, either tongue or groove, is attached to the outer contour of the component, in particular the MEMS chip, and the associated complementary structure (tongue or groove) is attached to the adjacent inner contour of a frame surrounding the component. The tongue and groove structure is advantageously formed using stacked and structured individual layers.The tongue and groove structure is subsequently separated both vertically and horizontally using an EPYC process by sacrificial layer etching using a release or exposure process for silicon and / or silicon oxide layers. After the components have been exposed, they no longer have a firm connection to the wafer assembly, but are essentially trapped in a cage both laterally and vertically. The exposed components, which in particular are MEMS chips fully covered with MEMS structures, can move slightly within this cage. Depending on the thickness of the sacrificial layers, the range of movement can be only a few micrometers.Due to the limited freedom of movement, the MEMS chips are held in their positions within the wafer, so that the absorption of forces that occur, for example, when soldering or bonding ASICs on the MEMS backside or through contact needles during electrical measurements with or without ASIC is possible.

[0044] The solution proposed according to the invention advantageously enables a second aspect to be realized, namely the removal of the MEMS chips from the cage formed by the silicon material of the wafer composite (singling). For removal, the cage or a frame is opened, and the spring elements are pulled out of the groove elements of the tongue and groove structure by moving all sides of the frame laterally away from the component. The lateral removal of the frame sides from the component is achieved by expanding an expandable base, for example, a tape, to which the wafer or wafer composite was previously laminated.Using this separation technique, it is possible to keep the MEMS chips in the wafer assembly, thus enabling subsequent processes such as electrical testing or ASIC bonding, while also protecting the sensitive, full-surface MEMS structures on top of the MEMS chips from contact. This also enables the handling of the MEMS chips, allowing them to be mounted on a substrate with a high optical fill level within an array, or to build the array on the substrate.

[0045] According to a further, third aspect of the present invention, a handling concept is proposed for MEMS chips that have full-surface, movable, or highly sensitive MEMS structures, particularly on their upper side. According to this third aspect of the solution proposed according to the invention, L-shaped handling surfaces are attached laterally to the full-surface MEMS chips. These handling surfaces are made of crystalline silicon and can therefore be removed after assembly by stealth dicing. L-shaped handling surfaces are formed from a partial surface of the electronic component(s) mounted beneath the MEMS chip, particularly by the edges of the ASICs, with edge regions of the ASIC(s) projecting beyond two adjacent MEMS chips at the sides. This creates a stepped edge contour in the cross-sectional profile of the MEMS chip and the ASIC edge.On the opposite MEMS chip sides, the edge of the ASIC(s) is offset inward relative to the edge structure of the MEMS chip, creating a complementary, stepped edge contour of the MEMS-ASIC chip assembly. If two MEMS-ASIC chips are mounted side by side on a substrate to form a MEMS array, the edge structures fit together and allow the MEMS chips to be placed side by side with virtually no gap, resulting in an extremely high optical fill factor.

[0046] Since the ASIC is made of a crystalline material, it is possible to separate the ASIC edge regions that protrude beyond the edge of the MEMS chip on the outer chips, formed from MEMS and ASIC, of ​​a composite array mounted on a substrate using stealth dicing.

[0047] Short description of the drawings

[0048] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0049] Shown are: Figure 1.1 an assembly of MEMS chips with full-area, sensitive structures and with ASICs arranged on their backside on a substrate,

[0050] Figure 1.2 shows a schematically illustrated handling device, placed on a protruding edge of ASICs,

[0051] Figure 2 shows a side view of the handling of a composite of MEMS chip and ASIC and their placement on a substrate with a handling device applied laterally to a staircase structure,

[0052] Figure 3 shows an ASIC in plan view with active area and L-shaped handling edge,

[0053] Figure 4 is a schematic representation of a separation of the protruding edge from the ASIC,

[0054] Figures 5.1 to 5.8 show a schematic representation of a wafer assembly with separation of MEMS chips and a lateral expansion connection during the release of the MEMS chip from the wafer assembly in side and top views,

[0055] Figures 6.1 to 6.4 show a side view of an embodiment of the wafer, in particular a pre-structured silicon wafer with a protective wafer, as well as a process sequence,

[0056] Figures 7.1 to 7.7 show a representation of process steps in the isolation of a MEMS chip from a wafer composite by sacrificial layer etching with separable frame elements of a frame structure in side views and in plan views,

[0057] Figures 8.1 to 8.8 show a variant of a manufacturing process with a protective wafer applied to the front side of the wafer with specifically introduced weakening zones and its separation during the singulation of the MEMS chip in side views and in plan views. Figure 9 shows possible arrangements of the weakening zones on a protective wafer and a frame-shaped profile of a bond frame representing a bond connection.

[0058] Figure 10 shows the top view of a MEMS chip with L-shaped handling surfaces attached to the side,

[0059] Figure 11 shows an arrangement of several MEMS chips with laterally formed handling edges according to Figure 10 in an adjacent arrangement and with compensation layers arranged on the underside,

[0060] Figure 12 shows a representation of a replacement layer on a bottom side of an adjacent MEMS chip and a handling surface,

[0061] Figures 13.1 to 13.6 Process steps of a process flow with tongue and groove structures formed in the wafer, laterally attached L-shaped handling surfaces, electronic components mounted on the back of the wafer as well as the composite by a laterally expandable base and

[0062] Figures 14.1 and 14.2 show the placement of a number of MEMS chips on an expandable substrate to form a wafer assembly.

[0063] Embodiments of the invention

[0064] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0065] Figure 1.1 shows that MEMS chips 120 are arranged on the top side of a substrate 160 in the form of a MEMS array 110, forming a high optical fill factor. As can be seen from Figure 1.1, the individual MEMS chips 120, which are arranged adjacent to one another, form said MEMS array 110. The individual MEMS chips 120 are fabricated from a wafer 100. Reference numeral 120' designates a MEMS chip to be transferred into the MEMS array 110 for its construction. As can also be seen from the illustration in Figure 1.1, electronic components 130, which are preferably ASICs, are arranged on the underside of each of the MEMS chips 120. These components protrude laterally beyond the edge of the MEMS chip 120 with their projecting edges 131. Figure 1.1 further shows that the projecting edges 131 of the electronic components 130 preferably protrude beyond the edge of the MEMS chip 120 to two adjacent sides and represent a surface suitable for handling.

[0066] Figure 1.2 shows a schematic representation of a handling tool in the form of a transfer device 180. In the state of the transfer device 180 shown in Figure 1.2, this is placed on top of the protruding edges 131 of the electronic components 130, preferably ASICs. The protruding edges 131 preferably extend along two adjacent sides of the MEMS chip 120. By means of a transfer device 180, the grasped assembly of MEMS chip 120 and electronic component 130 is inserted into an existing array 110 as a MEMS chip 120' to be transferred.

[0067] Figures 1.1 and 1.2 show the assembly of MEMS chips 120 with full-area, sensitive MEMS structures 122 on their front side and with electronic components 130 in the form of ASICs on the back side into a MEMS array 110. Edge regions, i.e., the protruding edges 131 of the electronic components 130, protrude beyond the edge of the MEMS chip 120 on two adjacent sides and form a surface suitable for handling. Either one electronic component 130 in the form of an ASIC or several electronic components 130 per MEMS chip 120 can be used. The individual electronic components 130, which are preferably ASICs, are applied to the back side of the respective MEMS chips 120 to be singulated while still within the wafer assembly 274 of the wafer 100.

[0068] The electronic components 130 in the form of ASICs are attached to the back of the MEMS chips 120 such that two of the four adjacent chip edges protrude beyond the edge of the respective MEMS chip 120. The protruding surface is essentially L-shaped and forms a handling surface 240. On opposite sides, the chip edge of the electronic components 130 in the form of ASICs is drawn inward relative to the edge of the MEMS chip 120. The distance between the edge of the MEMS chip 120 and the protruding edge 131 of the electronic component 130 is dimensioned such that it is slightly larger than the protruding edge width of the electronic component 130 in the form of the ASIC on the opposite side (see Figure 2). Since the protruding edges 131 of the electronic components 130 in the form of ASICs are cut off at the outermost elements on the substrate 160 (seeFigure 4), the electronic component 130 has no active structures in these areas.

[0069] From the illustration in Figure 2, it can be seen that the protruding edge 131 of the outermost MEMS chip 120 in the MEMS array 110 on the substrate 160 would hinder the assembly of additional substrates 160 next to one another and would result in an unwanted gap. To enable the assembly of multiple substrates 160 and a MEMS array 110 made of them with a high optical fill factor, the protruding edge 131 of the outermost MEMS chips 120 on a substrate 160, which serves for handling, must be removed. Since the electronic component 130 in the form of the ASIC is made of crystalline silicon, stealth dicing can be used for this purpose. At this point in time - ie after the assembly of the composites consisting of MEMS chips 120 and electronic components 130 in the form of ASICs according to Figure 2 on the substrate 160, for example by soldering - the composites have a very high strength.The side view according to Figure 2 further shows in more detail the stepped edge structure 276 as well as the complementary stepped edge structure 278, which is a mirror image of the latter. The MEMS chips 120, as well as the MEMS chips 120' to be transferred, are those that have highly sensitive, movable and / or touch-sensitive MEMS structures 122 on their upper side, for example, micromirror elements. These are, as will be explained below, removed from the silicon material of a pre-structured wafer 100 and separated. The transfer device 180 shown in Figure 2 can, for example, be a pick-and-place tool, which can be used, for example, by magnetization to handle the composite of MEMS chips 120 and electronic components 130 in the form of ASICs by means of the protruding edge 131.The top view according to Figure 3 shows an electronic component 130 in the form of an ASIC with an active surface. Said protruding edges 131 of the material of the electronic component 130, in particular an ASIC, extend along a separation line designated by reference numeral 134 and form a support or attachment surface 132 for the gripping tool 182 of the transfer device 180, shown in Figures 1.2 and 2.

[0070] The enlarged illustration in Figure 4 shows that, for example, laser processing is used to separate the chip, as indicated by the arrows pointing to the separation line 134 on both sides. This separates the protruding edge 131 from the stepped edge structure 276 of the composite of MEMS chip 120 and electronic component 130. The substrate 160 thus forms a seal with a substrate 160 to be arranged adjacently on a MEMS array 110 without creating an undesirable gap. This allows multiple substrates 160 populated with MEMS chips 120 to be installed on a MEMS array 110 with a high optical fill factor.

[0071] The sequence of figures 5.1 to 5.8 shows the isolation or separation of individual MEMS chips 120 from a material of the wafer 100 in side view and top view.

[0072] From the illustration in Figure 5.1, it can be seen that the wafer 100 is, for example, one that is designed as a pre-structured silicon wafer and constructed in a single-layer design 275. The design of the wafer 100 as a pre-structured silicon wafer in a single-layer design 275 makes it possible to form a tongue and groove structure 150, 152 during the construction of the wafer 100. The tongue and groove structures 150, 152 created between the component to be released later, namely the MEMS chip 120, and the remaining portion 100' of the wafer 100, fix a MEMS chip 120, which has been removed as described below, within the wafer 100.

[0073] The illustration in Figure 5.1 shows that touch-sensitive MEMS structures 122 extend along the top side of the MEMS chip 120. These are surrounded by filled etched structures 105 in a substantially rectangular shape, as can be seen from the illustration in Figure 5.2. Figure 5.2 further shows that the touch-sensitive MEMS structures 122 essentially completely cover the entire surface of the MEMS chip 120.

[0074] Figure 5.3 shows that after the MEMS chip 120 has been exposed according to method step d), outwardly exposed sacrificial layers in the form of the filled etched structures 105, made of silicon or of silicon oxide with silicon, are removed by RIE etching in SFe and / or XeF2. Alternatively or in addition, oxide sacrificial layers can be removed by RF gas phase etching. After the etching process, i.e. after the exposure step according to method step d), previously solid structures made of the wafer material will then be movable and will thus be very sensitive to vibrations, contact, and other external influences. During the exposure process, as a comparison of Figures 5.1 and 5.3 shows, the laterally circumferential, filled etched structures 105 between the tongue and groove structure 150, 152 on the outer contour of the MEMS chip 120 are removed.The MEMS chips 120 thus released are then located within a cage 202 and can only move laterally within this cage 202 by a few micrometers. By holding the MEMS chips 120 within the cage 202 in this way, the MEMS chips 120 largely retain their position within the wafer assembly 274.

[0075] From the top view according to Figure 5.4, it can be seen that the full-surface region on the top side of the MEMS chip 120, which is essentially completely covered with the touch-sensitive MEMS structures 122, is now no longer surrounded by filled etching structures 105, but by an exposed edge, namely said exposed etching structures 105'.

[0076] Figure 5.5 shows that after the MEMS chip 120 has been released within the wafer 100, its rear side 196 is applied to the top of an expanding base 190. The expanding base 190 can be, for example, a tape, an adhesive tape, or the like, which is capable of executing a lateral expansion movement 192, as indicated in Figure 5.5 by the laterally directed arrows. Due to the lateral expansion movement 192, the remnants 100' of the wafer 100, with their springs 150 on their inner contour, are moved laterally out of the outer contour of the MEMS chip 120, i.e., the springs 150 (the grooves 152?). Thus, the MEMS chip 120, which is arranged essentially centrally within the cage 202, is free and can be removed from the top side of the expandable base 190 as part of a vertical removal 226 described below.

[0077] The top view according to Figure 5.6 shows the separation of the MEMS chip 120 with its touch-sensitive MEMS structures 122 on the top side. Due to the expandability of the expandable base 190 in the radial and lateral directions and in an X / Y plane, the remnants 100' of the wafer material can be removed from the MEMS chip 120 to such an extent that its handling is enabled, in particular access by means of a transfer device 180 having a gripping tool 182, as schematically illustrated in Figures 1.2 and 2.

[0078] Figure 5.7 shows a state before performing a sacrificial layer etching to remove the filled etching structures 105 between the MEMS chip 120, on the one hand, and the remaining portion 100' of the wafer 100. After removing a sacrificial layer in the form of a silicon oxide layer 280, the exposed etching structures 105' create a free space in the form of the tongue and groove structure 150, 152 between the remaining portion 100' of the wafer 100, on the one hand, and the edge region of the MEMS chip 120 with touch-sensitive MEMS structures 122 located thereon.

[0079] Figure 5.8 shows that in this embodiment, the filled etched structures 105 are provided by at least one silicon oxide layer 280 and one silicon layer 290. After performing the etching process, the silicon layer 290 is first removed, and after performing a further etching process, the silicon oxide layers 280 are removed, resulting in the exposed etched structures 105. This creates the cage 202, within which a slight lateral mobility of the MEMS chip 120 is possible. The smaller this tolerance can be kept, the more precise handling can be achieved. In the illustration according to Figures 5.7 and 5.8, the filled etched structures 105 are provided by a silicon oxide layer 280 and at least one silicon layer 290. However, the silicon layer 290 could also be surrounded on both sides by a silicon oxide layer 280 each, so that the etched structures 105 shown in Figure 5.8 can be set. The sequence of figures 6.1 to 6.4 shows a process flow for producing a MEMS chip 120 from a wafer 100, in which the wafer 100 is provided on its front side 194, for example, with a protective wafer 198.

[0080] Figure 6.1 shows that wafer 100, preferably provided as a pre-structured silicon wafer, accommodates said at least one protective wafer 198 on its front side 194 by means of one or more bond connections 204. This protective wafer essentially covers the touch- and damage-sensitive MEMS structures 122 of the MEMS chip 120 to be exposed in wafer 100. The at least one protective wafer 198 is attached to the front side 194 of wafer 100 via bond connections 204. The MEMS chip 120 placed in wafer 100 can be removed by means of said filled etching structures 105, also described in connection with Figures 5.1 to 5.6.

[0081] Figure 6.2 shows that the at least one protective wafer 198 has a cavity 216 or a plurality of openings for etching media in the region of the MEMS structure 122 on the top side of the MEMS chip 120, which are required for carrying out the release step. Alternatively, the at least one protective wafer 198 can be formed without a cavity or can have a full-surface opening that extends over the MEMS structures 122 arranged over the entire surface of the top side of the MEMS chip 120.

[0082] According to Figure 6.2, the MEMS chip 120 is exposed according to method step d), after which outwardly exposed sacrificial layers in the form of silicon or silicon oxide are removed by means of RI E-etching in SFe and / or XeF2. Alternatively or additionally, the oxide sacrificial layers of the filled etched structures 105 can also be removed using RF gas-phase etching. Here, too, previously fixed structures in the wafer material of the pre-structured silicon wafer can be movable and are thus extremely sensitive to vibrations and contact. During the exposure process according to Figure 6.2, the laterally circumferential filled etched structures 105 between the tongue and groove structures 150, 152 on the outer contour of the MEMS chip 120 are removed. In this embodiment, the MEMS chip 120 is now also analogous to the representation in Figure 5.3 is held and essentially fixed within the cage 202 and is capable of only small lateral movements on the order of a few micrometers. Due to the arrangement of the released MEMS chips 120 within the wafer assembly 274, they can essentially maintain their position within the wafer assembly 274.

[0083] Figure 6.3 shows that, after the release according to Figure 6.2, the wafer composite 274 is applied to the top side of the expandable base 190. Subsequently, the bond connection 204 between the front side 194 of the wafer 100 and the back side of the at least one protective wafer 198 is released (debonded). The at least one protective wafer 198 is removed upward in a vertical direction.

[0084] According to Figure 6.4, after the removal of at least one protective wafer 198, a lateral expansion movement 192 of the expandable base 190 takes place radially or in the X / Y direction. In doing so, the components accommodated on the upper side of the expandable base 190, namely the MEMS chip 120 and the remnants of the wafer 100', are pulled apart so that the MEMS chip 120, which is released centrally within the cage 202 of the wafer 100, can be removed in the vertical direction. The expansion of the expandable base 190 continues until the springs 150 have completely moved out of the grooves 152 on the outer contour of the MEMS chip 120. Only then can the released MEMS chip 120, as shown in Figure 6.4, be removed from the wafer assembly 274 essentially in the vertical direction.

[0085] The sequence of figures 7.1 to 7.7 shows an embodiment of the method according to figures 6.1 to 6.4. In the method variant shown in the sequence of figures 7.1 to 7.7, a frame structure 206 is integrated into the material of the wafer 100, which is preferably designed as a pre-structured silicon wafer. The frame structure 206 comprises a number of frame elements, namely a first frame element 208, a second frame element 210, a third frame element 212 and a fourth frame element 214, as indicated in the plan view according to figure 7.7. All frame elements 208 to 214, of which only the first frame element 208 and the second frame element 210 are shown in the illustration according to figure 7.1, are integrated into the material of the wafer 100 by filled etching structures 105.Analogous to the preceding figures, the MEMS chip 120 to be cut out of the wafer 100 is one which has touch- or damage-sensitive MEMS structures 122, for example micromirror elements, on its upper side.

[0086] The illustration in Figure 7.2 shows a plan view of wafer 100, shown from the side in Figure 7.1. The MEMS structures 122, which essentially completely cover the top side of the MEMS chip 120, are completely enclosed by the frame structure 206 with its frame elements 208, 220, 212, 214.

[0087] Figure 7.3 shows that at least one protective wafer 198 is applied to the front side 194 of the wafer assembly 274 via several frame-shaped bond connections 204, which are not shown in the plane of the drawing according to Figure 3. This protective wafer comprises several openings 200.

[0088] The top view according to Figure 7.4 shows that after an etching process, in which sacrificial layers exposed to the outside are removed to expose the MEMS chip 120, silicon is dissolved out by means of RI E-etching in SFe, in XeF2, or silicon oxide in HF in the gas phase. In this process, previously solid silicon structures become mobile and extremely sensitive to vibrations, contact, or other external influences. During the release process, as indicated in Figure 7.3, the laterally circumferential filled etching structures 105 become exposed etching structures 105', analogous to the previous figures, so that the aforementioned frame structures 208 and 210 are exposed between the grooves 152 running along the outer contour of the MEMS chip 120 and the springs 150 arranged complementarily to these grooves. This is illustrated in Figures 7.3 and 7.5.

[0089] Figure 7.4 shows in detail the exposed frame elements 208, 210, 212, 214, which frame-like enclose the MEMS structures 122 on the top side of the MEMS chip 120. In the state illustrated in Figure 7.3, the individual components, in particular the remainders 100' of the wafer 100, the first frame element 208, the second frame element 210, and the further remainder 100' of the wafer 100, are still connected to the at least one protective wafer 198 via said bond connections 204. As shown in Figure 7.5, the wafer composite 274 is laminated to the top side of the expandable base 190, and the temporary bond connections 204 between the front side 194 of the wafer 100 or its components and the underside of the at least one protective wafer 198 are released by debonding, so that the at least one protective wafer 198 can be removed in the vertical direction. After applying the wafer composite 274 according to Figure 7.5 onto the expandable base 190 and the removal of at least one protective wafer 198, a lateral expansion movement 192 takes place according to Figure 7.6. This continues until the individual tongue / groove structures 150, 152 between the frame elements 208 and 210 of the frame structure 206 and the remainders 100' of the wafer 100 and the outer contour of the MEMS chip 120 to be exposed are completely disengaged.

[0090] This state is indicated in the plan view according to Figure 7.7, in which the centrally arranged MEMS chip 120 is completely free of the frame elements surrounding it, namely the first frame element 208, the second frame element 210, the third frame element 212 and the fourth frame element 214 of the frame structure 206.

[0091] The sequence of Figures 8.1 to 8.8 shows an embodiment of the method proposed according to the invention, according to which a MEMS chip 120 is released from the wafer 100 without the at least one protective wafer 198 covering the full-surface MEMS structures 122 of the MEMS chip 120 being removed as a whole. Rather, the protective wafer 198 is not removed as a whole component, but in individual parts, namely together with the frame elements 208-214 of the frame structure 206, without the temporary connection in the form of a bond connection 204 being released. It should be emphasized here that a temporary, i.e. detachable, connection of the protective wafer 198 is created by means of the temporary bonding method.

[0092] Figure 8.1 shows that wafer 100, which is preferably a pre-structured silicon wafer, accommodates said MEMS chip 120. The MEMS chip 120 is connected to further sections of the material of wafer 100 via the filled etched structures 105. Figure 8.2 shows a top view of this state, illustrated in the side view in Figure 8.1, according to this alternative embodiment of the method proposed by the invention.

[0093] According to Figure 8.3, at least one protective wafer 198 is applied to the front side 194 of the wafer 100, which has a cavity 216 on its rear side 215. The cavity 216 forms a membrane 218 between the lateral cheeks of the at least one protective wafer 198. The cavity 216 is dimensioned such that it essentially protects the MEMS structures 122, which completely cover the top side of the MEMS chip 120, from external damage.

[0094] In addition to the cavity 216, trench-shaped weakening zones 220 are formed on the rear side 215 of the at least one protective wafer 198 on several sides around the cavity 216. These trench-shaped weakening zones 220 can be produced together with the cavity 216, for example, using the RIE etching process. A width of slots decreasing with a depth 221 of this trench-shaped weakening zone 220, as well as the desired depth 221 of the trench-shaped weakening zone 220, can be adjusted using the ARDE effect (Aspect Ratio Dependent Etch). The geometry of the trench-shaped weakening zones 220, in particular their position on the at least one protective wafer 198, defines subsequent separating lines 222, as indicated in Figure 8.4. The trench-shaped weakening zones 220 in the material of the at least one protective wafer 198 define the separating lines 222.If these are missing on one side, the membrane 218 remains bonded to one side of the wafer material above the cavity 216 even after the lateral expansion movement 192. To ensure this mechanical connection, no trench-shaped weakening zone 220 is introduced on this side between the bond connection 204 on the one hand and the MEMS structure 122 on the other.

[0095] Figures 8.3 and 8.4 show that during the release of the MEMS chip 120 according to method step d), outwardly exposed sacrificial layers in the form of the filled etched structures 105, formed by silicon or silicon oxide, are removed by RIE etching in SFe and / or XeF2. Alternatively or additionally, oxide sacrificial layers are removed by RF gas-phase etching. This makes previously solid silicon structures move and thus extremely sensitive to vibrations and contact. During the release process according to method step d) and the illustration according to Figure 8.3, the laterally circumferential filled etching structures 105 are dissolved, whereby the tongue and groove structure 150, 152 is released and a free space is created on the outer contour of the MEMS chip 120, but the released and removed MEMS chip 120 remains held and only minimal movement is possible.The MEMS chips 120 thereby retain their position within the wafer assembly 274.

[0096] After the MEMS chip 120 has been exposed according to Figure 8.3, it is laminated to the top side of the expandable base 190, as shown in Figure 8.5. During the lateral expansion movement 192 of the base, both the tongue and groove structure 150, 152 is released and the at least one protective wafer 198 is separated in the region of its trench-shaped weakened zones 220, indicated by a separation gap 224 in Figure 8.5, which is also shown in the plan view according to Figure 8.6. In the state shown in Figure 8.5, the individual parts of the protective wafer 198 are still connected to the front side 194 of the parts of the wafer 100, namely the remnants 100', via the temporary bond connections 204.

[0097] Figure 8.7 shows that after the lateral expansion movement 192 of the expandable base 190 and the separation of the at least one protective wafer 198 along the trench-shaped weakening zones 220, the tongue and groove structure 150, 152 is disengaged. Separation of the at least one protective wafer 198 along the trench-shaped weakening zones 220, as shown in Figure 8.6, can additionally or alternatively be performed by stealth dicing. The separated components, i.e., the parts of the at least one protective wafer 198 and the remnants 100' of the wafer 100, can be removed from the top side of the expandable base 190 together with the parts attached to them during a vertical removal movement 226. Only the exposed and separated MEMS chip 120 remains on the top side (see Figure 8.8).All separated components are removed from the exposed MEMS chip 120, as can be seen from a comparison of the top views in Figures 8.6 and 8.8.

[0098] Figure 9 shows possible arrangements of the trench-shaped weakening zones 220. A bond frame 228 can be seen in all sub-figures of Figure 9. The bond frame 228 represents an embodiment of the temporary bond connections 204, with which the at least one protective wafer 198 is attached to the front side 194 of the material of the wafer 100. This is achieved by bonding. The bond connection 204 shown here is not a temporary one, but rather a permanent bond connection 204. The various sub-figures of Figure 9 show that paths 230 of the trench-shaped weakening zones 220 can be formed parallel to one another, or that the trench-shaped weakening zones 220 can be crossed. Various embodiments are possible here.The courses 230 of the trench-shaped weakening zones 220 also depend on the separation properties of the at least one protective wafer 198, which, with its cavity 216 formed on its rear side 215, protects the MEMS structures 122 applied over the entire surface to the top side of the MEMS chip 120 against external influences.

[0099] Figure 10 shows a top view of a singled MEMS chip 120, the top side of which is essentially completely covered with MEMS structures 122. Figure 10 shows that the MEMS chip 120 shown here comprises laterally attached handling surfaces 240. The handling surfaces 240 are essentially L-shaped 250 and comprise a first leg 252 and a second leg 254 extending at right angles thereto. The L-shaped handling surface 240 is connected to the material of the MEMS chip 120 by a number of bridge webs 256.

[0100] Figure 11 shows the arrangement of a number of MEMS chips 120. In this schematic side view, the MEMS chips 120 can be arranged side by side within an array 110. As can be seen from the schematic illustration in Figure 11, a MEMS chip plane 260 is formed, below which a plane 262 for handling extends. As can be seen from the illustration in Figure 11, either electronic components 130 in the form of ASICs are attached to the underside of the MEMS chips 120, or replacement layers 258 (dummy layers) are located on the underside. These achieve a uniform height and compensate for height differences between the handling surfaces 240 on the one hand and the adjacent MEMS chips 120 on the other.From the illustration in Figure 11, it can be seen that, for example, the handling surface 240 is connected to the MEMS chip 120, as shown in Figure 10, via the bridge web 256. Within the plane 262 for handling, the handling surface 240 engages a handling surface 270 of an adjacently arranged MEMS chip 120 by means of a projection.

[0101] Figure 12 shows an arrangement between adjacent MEMS chips 120 in more detail. A handling surface of an adjacent MEMS chip 120 is designated by reference numeral 270, below which extends the aforementioned plane 262 for handling during a singulation process.

[0102] The sequence of figures 13.1 to 13.6 shows a process flow in which the tongue and groove structures 150, 152 and laterally attached handling surfaces 240 for the handling and assembly of electronic components 130 in the form of ASICs are shown.

[0103] Figure 13.1 shows a wafer 100 having said MEMS structures 122 on its front side. Handling surfaces 240 and handling surfaces 270 of an adjacent MEMS chip 120 are provided in the solid material of the wafer 100, which is preferably provided as a pre-structured silicon wafer.

[0104] Figure 13.2 shows that at least one protective wafer 198 is applied to the front side of wafer 100. The handling surfaces 240 are connected, for example, via the bridge webs 256 to the MEMS chip 120 to be exposed and removed. The at least one protective wafer 198 is attached to the front side of wafer 100 via a temporary bond connection 204 (not shown in detail here).

[0105] Figure 13.3 shows the release of the MEMS chip 120. Located on the rear side 215 of the at least one protective wafer 198 is the aforementioned cavity 216, which essentially covers the touch- and damage-sensitive MEMS structures 122 on the front side of the MEMS chip 120. The at least one protective wafer 198 is temporarily bonded in the region of the upper sides of the handling surfaces 240. The release of the MEMS chip 120 from the wafer assembly 274 is carried out by means of the etching processes already described above of outwardly exposed sacrificial layers, whether silicon oxide or silicon oxide with silicon, using RI E-etching in SFe and / or XeF2. Alternatively or additionally, oxide sacrificial layers (cf. filled etch structures 105) can be removed by means of HF vapor-phase etching. This results in the release of the MEMS chip 120 shown in Figure 13.3.On one side, here the left side of the handling surface 240, is the protruding tongue 150, which engages in the groove 152 on the outer contour of the exposed MEMS chip 120. On the back side 196 of the wafer 100, a contacting needle 272 is indicated, which serves for the electrical testing or measurement of the exposed MEMS chip 120. Reference numeral 256 denotes a bridge web, made essentially of remaining silicon material, between the outer contour of the MEMS chip 120 and the handling surface 240. This, in turn, is connected to a handling surface 270 of an adjacent MEMS chip 120, for example, via a tongue and groove structure 150, 152.

[0106] The illustration in Figure 13.4 shows that two electronic components 130 in the form of ASICs are applied to the backside 196 of the exposed MEMS chip 120. These can be electrically tested using the contact pins 272. To compensate for the height difference, replacement layers 258 are applied to the underside of the handling surfaces 240 and 270 with a thickness identical to that of the electronic components 130 in the form of ASICs.

[0107] Subsequently, the composite according to Figure 13.5, including its replacement layers 258 and the electronic components 130 in the form of ASICs, is laminated onto the top side of the expandable base 190. Subsequently, the temporary bond connections 204 between the top sides of the handling surfaces 240 and the at least one protective wafer 198 covering the touch- and damage-sensitive MEMS structures 122 on the top side of the MEMS chip 120 are released. The at least one protective wafer 198 is removed.

[0108] Finally, Figure 13.6 shows that the expandable base 190 now performs a lateral expansion movement 192. During this lateral expansion movement 192, the handling surfaces 240 and the groove 152 formed thereon are moved laterally out of the spring 150 in the outer contour of the MEMS chip 120. However, the handling surface 240 remains connected to the MEMS chip 120 via the aforementioned bridge web 256. The electronic components 130 in the form of ASICs are still located on the underside of the chip. At the same time, the handling surface 270 of an adjacent MEMS chip 120 is also moved out of the lateral handling surface 240, which is contacted by the tool 182 for gripping, due to the lateral expansion movement 192. Now, a lifting, i.e.A vertical removal 226 of the released MEMS chip 120 can be performed upwards, which can be done, for example, using a pick-and-place tool and the handling surface 240, which is still connected via the bridge web 256. After the MEMS chip 120 has been placed in this manner, the bridge web 256, indicated by the arrow, is separated by the action of a laser and after the MEMS chip 120 has been placed on a substrate 160.

[0109] Figure 14.1 shows the MEMS chips 120 on the expandable base 190 before expansion thereof, and Figure 14.2 shows the state after expansion of the expandable base 190.

[0110] Furthermore, the invention relates to the use of the method for producing and handling, in particular for isolating and singulating MEMS chips 120, which are arranged to form a MEMS array 110 while maintaining a high optical fill factor.

[0111] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art.

Claims

Claims 1 . Method for producing and handling MEMS chips (120) with MEMS structures (122) extending substantially over the entire surface thereof, comprising at least the following method steps: a) providing a pre-structured wafer (100) with a number of pre-structured MEMS chips (120), b) forming a substantially circumferential tongue and groove structure (150, 152) in the pre-structured wafer (100) between an outer contour of a component, in particular a MEMS chip (120) and a complementary inner contour of a frame structure (206, 208-214), or parts (100') of the wafer (100), c) applying at least one protective wafer (198) to one side of the wafer (100) by means of a temporary joining process, d) exposing a MEMS chip (120) from the pre-structured wafer (100) by means of a Etching process of filled etching structures (105),e) holding released MEMS chips (120) within a cage (202) in the pre-structured wafer (100); and f) removing the MEMS chips (120) held according to method step d) from the pre-structured wafer (100) by vertical removal (226) after a local expansion (192).

2. Method according to claim 1, characterized in that the pre-structured wafers (100) are produced by means of a single-layer structure (275).

3. Method according to one of the preceding claims, characterized in that the pre-structured wafer (100) is provided with at least one protective wafer (198) on its front side (194) by means of temporary bonding by forming a bond connection (204), or the at least one protective wafer (198) is applied by means of a permanent bond (204) and the at least one protective wafer (198) is separated into parts during the lateral expansion movement (192) and these parts are removed together with frame elements (208-214) of a frame structure (206).

4. Method according to one of the preceding claims, characterized in that during the release according to method step c) filled etched structures (105) are formed between the inner contour and the outer contour of the substantially circumferential tongue and groove structure (150, 152) should be removed.

5. Method according to one of the preceding claims, characterized in that according to method step c) exposed sacrificial layers, in particular silicon or silicon oxide with silicon, are dissolved out by means of an etching process in SFe or XeF2 and / or oxide sacrificial layers are removed by HF gas phase etching.

6. Method according to one of the preceding claims, characterized in that after carrying out method step c), the MEMS chip (120) is laterally and vertically movable within a cage (202) and is held in exposed etching structures (105'), tongue and groove structures (150, 152) forming the inner contour and the outer contour, respectively.

7. Method according to one of the preceding claims, characterized in that after carrying out method step c), the wafer (100) is laminated on its rear side (196) to an expandable base (190).

8. Method according to one of the preceding claims, characterized in that according to method step c) the expandable base (190) carries out an expansion movement (192) laterally, radially or in an X and Y direction, during which the tongue and groove structures (150, 152) are disengaged.

9. Method according to claim 3, characterized in that the at least one protective wafer (198) is provided on its rear side (215) facing the front side (194) of the wafer (100) with a cavity (216) and at least one trench-shaped weakening zone (220).

10. The method according to claim 9, characterized in that the at least one trench-shaped weakening zone (220) and the cavity (216) are produced by means of an etching process.

11. Method according to claims 9 and 10, characterized in that a decreasing slot width is set by means of a depth (221) of the at least one trench-shaped weakening zone (220) and / or the depth (221) of the at least one trench-shaped weakening zone (220) is set such that separating lines (222) are defined in the at least one protective wafer (198) during a lateral expansion movement (192).

12. Method according to claims 9 to 11, characterized in that a membrane (218) of the protective wafer (198) is formed on at least one side of the cavity (216) which is free of weakening zones and remains connected during the lateral expansion movement (192).

13. Method according to claims 9 to 12, characterized in that during the lateral expansion movement (192) parts (100') of the wafer (100) are separated laterally and the at least one protective wafer (198) is separated along the separation line (222).

14. Method according to claims 9 to 13, characterized in that during the lateral expansion movement (192) frame elements (208-214) of the frame structure (206) are separated.

15. Method according to claims 9 to 14, characterized in that the separated frame elements (208-214) and the parts (100') of the wafer (100) are removed from the expandable base (190), in particular by a vertical removal (226).

16. Method according to one of the preceding claims, characterized in that the at least one temporary bond connection (204) is formed in the form of a bond frame (228).

17. Method according to one of the preceding claims, characterized in that the at least one trench-shaped weakening zone (220) in the at least one protective wafer (198) has courses (230) which are either parallel to one another or crossed with one another.

18. Method according to one of the preceding claims, characterized in that during the release of the MEMS chips (120) according to method step c), handling surfaces (240) remain in the material of the wafer (100), which are formed substantially in an L-shape (250), having a first leg (252) and a second leg (254) running at right angles to the first leg.

19. Method according to one of the preceding claims, characterized in that during the release of the MEMS chips (120) according to method step c) in the material of the wafer (100) with the production of the handling surfaces (240), the tongue and groove structure (150, 152) is released.

20. Method according to one of the preceding claims, characterized in that electronic components (130), in particular ASICs, are placed on the back side (196) of the wafer (100) and the handling surfaces (240) and handling surfaces (270) of adjacent MEMS chips (120) are provided with a replacement layer (258) whose thickness substantially corresponds to a thickness of the electronic components (130), in particular ASICs.

21. Method according to the preceding claim, characterized in that the handling surfaces (240, 270) are formed by projecting edges (131) of the electronic components (130), in particular the ASICs, which are placed on the back side (196) of the MEMS chips (120) in the wafer (100).

22. Method according to claims 20 and 21, characterized in that in the cross section of the MEMS chips (120) by projecting edges (131) of the electronic components (130), in particular the ASICs, and an edge (170) of the MEMS chips (120) a step-shaped edge structure (276) is formed.

23. Method according to claims 20 to 22, characterized in that the projecting edges (131) of the electronic components (130), in particular the ASICs, are formed on two adjacent sides of the MEMS chips (120).

24. Method according to the preceding claims 20 to 23, characterized in that a complementary step-shaped edge structure (278) is formed on the sides of the MEMS chip (120) opposite the two adjacent sides.

25. Use of the method according to claims 1 to 24 for the production and handling of MEMS chips (120).

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