DE102022209402A1 - Microelectromechanical device - Google Patents

Abstract

Microelectromechanical device (110) comprising a carrier substrate (100) with a substrate surface (100a) and a plurality of MEMS modules (120), each of the plurality of MEMS modules (120) having an ASIC layer (140) with an ASIC layer front side (140a) and an ASIC layer back (140b), a base plate (160) with a base plate front (160a) and a base plate back (160b) and a plurality of microelectromechanical components (130) with a component back (130b), the base plate ( 160) is arranged on the ASIC layer front side (140a) and the base plate back side (160b) is connected to the ASIC layer front side (140a) and the plurality of microelectromechanical components (130) are arranged on the base plate front side (160a) and their component back sides ( 130b) are connected to the front side of the base plate (160a), the ASIC layer (140) having an ASIC for controlling the plurality of microelectromechanical components (130), the ASIC being connected to the microelectromechanical components (130) via electrical contacts (144). , wherein the plurality of MEMS modules (120) are arranged on the substrate surface (100a) and the ASIC layer backs (140b) of the plurality of MEMS modules (120) are connected to the substrate surface (100a).

Description

The present invention relates to the field of microelectromechanical devices, in particular micromirror arrays, and relates to a microelectromechanical device, illumination optics, an illumination system for a projection exposure system, a corresponding projection exposure system and a method for producing a microelectromechanical device.

State of the art

The use of devices with movable micromirrors arranged in a matrix, so-called micromirror arrays or micromirror actuators, is now used in a variety of devices, for example in smartphones, projectors, head-up displays, barcode readers, mask exposure devices in semiconductor production and microscopes. Corresponding micromirror arrays are, for example, from the writings DE 10 2013 208 446 A1 , EP 0 877 272 A1 and WO 2010/049076 A2 known. Disclosures regarding suitable actuator devices for displacing the individual mirrors of a micromirror array, the micromirrors, are shown, for example DE 10 2013 206 529 A1 , the DE 10 2013 206 531 A1 and the DE 10 2015 204 874 A1 .

Disclosure of the invention

According to the invention, a microelectromechanical device, an illumination optics comprising such a microelectromechanical device as well as an illumination system and a projection exposure system, each with a corresponding illumination optics, as well as a method for producing a microelectromechanical device according to the invention are proposed.

According to a first aspect of the invention, a microelectromechanical device comprising a carrier substrate with a substrate surface and several MEMS modules is proposed (MEMS: microelectromechanical system). Each of the several MEMS modules includes an ASIC layer with an ASIC layer front side and an ASIC layer back side opposite this ASIC layer front side, a base plate with a base plate front side and a base plate back side opposite this base plate front side, and a plurality of microelectromechanical components a component back. The microelectromechanical components do not have to be identical in structure and/or function, although this can be the case. The base plate is arranged on the ASIC layer front side and the base plate back is connected to the ASIC layer front side. In particular, a cohesive connection by means of soldering or preferably sintering or eutectic bonding is suitable for this, through which electrical contacts are formed between the ASIC layer and the base plate. Silver sintering paste, for example, can be used as the sintering material. The several microelectromechanical components are further arranged on the front of the base plate and their component backs are connected to the front of the base plate. The ASIC layer of each of the MEMS modules has one or more ASICs (ASIC: application-specific integrated circuit) for controlling the plurality of microelectromechanical components, the one or more ASICs interacting with the microelectromechanical components using at least some of the electrical contacts are electrically connected, the electrical contacts typically being continued in the base plates to the microelectromechanical components by means of electrical connections, for example plated-through holes. For example, in order to produce electrical connections between further electronics located on the carrier substrate and the microelectromechanical components, the ASIC layer can optionally also include wiring carriers (interposers) and/or further elements in addition to ASICs. Electrical connections can be continued using electrical contacts between the ASIC layer and the base plate. In particular, silicon-based interposers with electrical connections, for example silicon vias (TSV, through-silicon via) such as copper-based vias (Cu vias), come into consideration as interposers. The plurality of MEMS modules are arranged on the substrate surface of the carrier substrate and the ASIC layer backsides of the plurality of MEMS modules are connected to the substrate surface. This connection is also typically made in a cohesive manner and is preferably carried out by sintering. The further electronics on the carrier substrate can be, for example, further ASICs for controlling the entire electromechanical device, passive components and/or connecting elements (such as plugs, cables), for example for establishing an electrical connection to external control devices such as a computing unit and to the power supply act. The carrier substrate serves overall as a component carrier and can include electrical connections, for example plated-through holes, for conducting electrical signals from one surface of the carrier substrate to another surface of the carrier substrate. For example, it can be advantageous to arrange the additional electronics on a substrate surface of the carrier substrate nen, which is opposite the substrate surface with the MEMS modules. Furthermore, to enable a high fill factor, i.e. a close arrangement of the MEMS modules on a carrier substrate, the ASIC layer of a MEMS module can be designed in such a way that it does not protrude laterally beyond the base plate of the MEMS module. The ASIC layer of a MEMS module therefore preferably has dimensions that are identical or smaller than the base plate.

Such a microelectromechanical device consequently divides its plurality of microelectromechanical components into individual groups, each of which includes several microelectromechanical components and are referred to as MEMS modules in the context of this invention. For example, the multiple MEMS modules can each have exactly 2, 3, 4, 5, 6, 9, 12, 16, 20, 25, 30, 36, 42, 49, 56, 64, 72 or 81 of the multiple microelectromechanical components, whereby other numbers ≥ 2 are also conceivable. The multiple microelectromechanical components can, for example, be arranged in a rectangular grid consisting of columns and rows, for example consisting of two columns and two rows, two columns and three rows, three columns and three rows, three columns and four rows, four columns and four rows, four columns and five rows, five columns and five rows, five columns and six rows, six columns and six rows, six columns and seven rows, seven columns and seven rows, seven columns and eight rows, eight columns and eight rows, eight columns , and nine rows or nine columns and nine rows. Alternatively, a hexagonal grid is conceivable, for example. An electromechanical device according to the invention can, for example, comprise exactly 2, 3, 4, 5, 6, 9, 12, 16, 20, 25, 30, 36, 42, 49, 56, 64, 72 or 81 MEMS modules, including others Numbers ≥ 2 are conceivable. The MEMS modules can also be arranged in a rectangular grid consisting of spades and rows, for example consisting of two columns and two rows, two columns and three rows, three columns and three rows, three columns and four rows, four columns and four rows, four columns and five rows, five columns and five rows, five columns and six rows, six columns and six rows, six columns and seven rows, seven columns and seven rows, seven columns and eight rows, eight columns and eight rows, eight columns , and nine rows or nine columns and nine rows. Alternatively, a hexagonal grid is also conceivable here.

An advantageous aspect of a microelectromechanical device structured in this way is that the structure is divided into MEMS modules, reducing the complexity and susceptibility to errors of the structure. Multiple MEMS modules with a reduced number of microelectromechanical devices were found to be easier to handle in the production process than a single unit with the same total number of microelectromechanical devices. In particular, an approach according to the invention can significantly increase the yield of the production process, since the MEMS modules that only contain fully functional microelectromechanical components can be specifically selected during production. Furthermore, it is conceivable that a large number of such microelectromechanical devices according to the invention are in turn connected to form a higher-level unit, for example in order to cover larger areas than is practicable with a single microelectromechanical device according to the invention.

A particularly important embodiment of the invention is the use of micromirrors as microelectromechanical components. The microelectromechanical device can therefore in particular be a micromirror array. In such a case, each of the plurality of microelectromechanical components comprises a mirror element with a reflection surface for reflecting light and a displacement device for displacing the mirror element of the respective microelectromechanical component, wherein the one or more ASICs are designed to control the displacement devices. Here, shifting means a movement with regard to at least one degree of freedom. Shifting can include both linear movements and rotations. The mirror element can in particular be or include a Bragg mirror. The displacement devices can be, for example, electrostatic actuators, for example with comb electrodes. For example, actuators like those in the documents come into question DE 10 2013 206 529 A1 , DE 10 213 206 531 A1 and DE 10 2015 204 874 A1 described.

A structure according to the invention of a microelectromechanical device into MEMS modules is particularly advantageous if the carrier substrate of the microelectromechanical device according to the invention consists essentially of a first material and the plurality of MEMS modules essentially consist of a second material, the first material having a first coefficient of thermal expansion α ₁ and the second material has a different, second coefficient of thermal expansion α ₂ . Typically, the first material, i.e. the material of the carrier substrate, comprises a ceramic, for example an Al ₂ O ₃ -based ceramic, or is a ceramic, for example an Al ₂ O ₃ -based one Ceramics. The second material, i.e. the material of the MEMS modules, typically comprises a semiconductor material, in particular silicon, for example monocrystalline and/or polycrystalline silicon, or is a semiconductor material, in particular silicon, for example monocrystalline and/or polycrystalline silicon. The invention can be used particularly advantageously when the first coefficient of thermal expansion α ₁ and the second coefficient of thermal expansion α ₂ have larger differences, for example when they have a ratio of α ₁ /α ₂ ≥ 1.5 to one another. As part of the production process of a microelectromechanical device such as a micromirror array, significantly higher temperatures typically occur, for example due to soldering or sintering, than in a resting state or an operating state of the device. If such devices are made from different materials that have different coefficients of thermal expansion (such as ceramic and silicon), mechanical stresses induced by the different coefficients of thermal expansion, also referred to as thermal stresses, may occur. Such thermal stresses are frozen during assembly (i.e. soldering or sintering) and reduced over the life of the device. This can cause deformation and/or damage to the structure of the device, which severely impairs its functionality. For example, in the case of a micromirror array, the positions of the individual mirrors can be changed unintentionally. By structuring the microelectromechanical components of a microelectromechanical device into spatially smaller MEMS modules made of a second material, which are applied to a carrier substrate made of a first material, these thermal stresses, which arise from the different materials used, can be compared to a corresponding microelectromechanical device from the prior art can be significantly reduced.

In order to obtain a particularly high coverage of the available area by the microelectromechanical components, it is advantageous if the plurality of MEMS modules have a substantially rectangular, preferably square base area and are arranged in a rectangular, preferably square grid. Alternatively, it is also advantageous if the MEMS modules have a substantially hexagonal base area and are arranged in a hexagonal grid. A substantially rectangular or hexagonal base area here means that minor deviations from a strictly rectangular or hexagonal base area are conceivable, for example due to rounded corners and/or indentations or bulges or other irregularities. It is particularly advantageous here if each MEMS module has only the smallest possible distance from its neighboring MEMS modules. For example, each of the plurality of MEMS modules can have a distance of ≤ 50 µm, preferably ≤ 10 µm, particularly preferably ≤ 5 µm to at least one neighboring MEMS module and preferably to all neighboring MEMS modules. An adjacent MEMS module of a MEMS module arranged in a grid is here a MEMS module also arranged in the grid, which is directly adjacent to the MEMS module, in the sense that there is between the MEMS module and the neighboring MEMS module. Module there is no other MEMS module in the grid. In the case of MEMS modules arranged in a rectangular grid, MEMS modules lying diagonally to one another are also to be understood as MEMS modules adjacent to one another. A footprint of a MEMS module is typically defined by the carrier substrate of the MEMS module.

Accordingly, it is also particularly advantageous if each of the several microelectromechanical components of each of the several MEMS modules has a substantially rectangular, preferably square or a substantially hexagonal base area. A substantially rectangular or hexagonal base area means that minor deviations from a rectangular or hexagonal base area are conceivable, for example through indentations and/or bulges at corners and/or edges of the base area such as rounded and/or beveled corners of the base area.

In order to be able to place, i.e. grip, move and/or position, the MEMS modules on the substrate surface during the production process using a suitable device (handling device), it must be possible to grip the MEMS modules without damaging them and in particular without particularly sensitive areas like touching reflective surfaces. For this purpose, the MEMS modules can each include at least one, for example two, preferably at least three, particularly preferably four or more handling areas that are not covered by the plurality of microelectromechanical components of the MEMS module. Here, a handling area is an area of a MEMS module that is suitable for being used by a handling device in order to be able to grip, move and/or position the MEMS module without damaging the MEMS module. Alternatively or in addition to handling areas, a MEMS module can be provided with a frame in which a suitable handling device (for example using negative pressure) can grasp the MEMS module and then move and/or position it. A MEMS module can also be provided with a frame that at least partially encloses the MEMS module, which is used when generating a negative pressure in the area of the frame in conjunction with a corresponding handling device that generates negative pressure. Alternatively or additionally, such a frame can also serve to avoid or at least reduce the penetration of dirt into the MEMS module. For example, such a frame could enclose the microelectromechanical components of a MEMS module without the handling areas. Such a frame can also be thinner than a frame that is designed so that the MEMS module can be gripped over it.

Each of the at least one handling areas of a MEMS module can be formed, for example, by a beveled or grooved (providing a groove) lateral edge of one of the plurality of microelectromechanical components of the MEMS module. In the context of this invention, a groove is to be understood as a recess along an edge. A groove can have any shape, for example round or rectangular. In the context of this invention, a lateral edge of a MEMS module is to be understood as meaning a vertically extending edge of the MEMS module. A side edge corresponds to a corner of a base area of the MEMS module. Lateral recesses (recesses in a side surface) of any shape (for example semicircular or rectangular) of a microelectromechanical component can also serve as handling areas, with such recesses in a side surface preferably being arranged centrally within the side surface. Due to their known positions within a MEMS module, handling areas can also be used to bring the MEMS module into a defined position in relation to the substrate and in particular also in relation to an adjacent MEMS module.

According to a further preferred embodiment, the microelectromechanical device comprises a plurality of flexible elements for reducing mechanical stresses between the plurality of MEMS modules, each of the plurality of flexible elements being part of a MEMS module of the plurality of MEMS modules and on and/or in a side surface thereof MEMS module is arranged. Such flexible elements are particularly advantageous if the MEMS modules are positioned with no or only a small distance from one another during the production process in order to achieve the highest possible proportion of the area of the carrier substrate occupied by the MEMS modules, i.e. a high fill factor. If mechanical tensions arise between the MEMS modules during the production process or later due to this small distance between them, these will be counteracted by the flexible elements. A flexible element for reducing mechanical stresses between at least two of the several MEMS modules therefore corresponds to a spring that counteracts the mechanical stresses with its restoring force. Mechanical stresses can occur in particular in the form of thermal stresses, which are caused by different thermal expansion coefficients of the materials used: If the first material from which the carrier substrate essentially consists (typically a ceramic, such as an Al ₂ O ₃ ceramic) is a has a larger coefficient of thermal expansion than the second material from which the MEMS modules essentially consist (typically a semiconductor material such as silicon), both the carrier substrate and the MEMS modules contract upon cooling, for example after a step within which takes place at higher temperatures the manufacturing process such as bonding. However, due to the lower coefficient of thermal expansion of the second material, this contraction occurs to a lesser extent for the MEMS modules than for the carrier substrate. As a result, there is a risk that two adjacent MEMS modules will be pressed against each other if they have been arranged at no or only a small distance from one another. A thermal tension is therefore built up between the MEMS modules, which can lead to damage to the microelectromechanical device. Such thermal stress can be counteracted by a flexible element. Overall, mechanical stability can be guaranteed with a high filling factor at the same time.

A particularly advantageous embodiment of a flexible element is given by the fact that each of the several flexible elements is arranged in a side surface of a MEMS module and comprises a web, the web being part of the side surface of the MEMS module and through a recess in the MEMS module. Module is formed and preferably has an external bulge, which can serve to produce a contact point to an adjacent MEMS module. In particular, such a flexible element can be realized by a recess in a base plate of a MEMS module. By building up such a base plate in layers During the production process, such flexible elements can be easily implemented.

Preferably, the plurality of MEMS modules each have one or more of the plurality of flexible elements, wherein the plurality of MEMS modules are arranged such that the one or more flexible elements of each of the plurality of MEMS modules are each adjacent to another MEMS module of the plurality MEMS modules are arranged. A flexible element of a MEMS module is arranged adjacent to another MEMS module when the other MEMS module is arranged adjacent to the MEMS module of the flexible element and the flexible element is oriented towards the adjacent MEMS module.

A particularly preferred embodiment of the invention is given in that a first MEMS module of the plurality of MEMS modules comprises a first base plate with at least a first flexible element of the plurality of flexible elements and a second MEMS module of the plurality of MEMS modules includes a second base plate at least one second flexible element of the plurality of flexible elements, wherein the first MEMS module and the second MEMS module are arranged relative to one another such that the at least one first flexible element is adjacent to the second base plate and the at least second flexible element is adjacent to the first Base plate is arranged. Here, a flexible element of a MEMS module is arranged adjacent to a base plate of another MEMS module, if the other MEMS module is arranged adjacent to the MEMS module of the flexible element, the flexible element is oriented towards the adjacent MEMS module and the flexible element is at the same height as the base plate of the other MEMS module. Preferably, the first and second flexible elements are arranged offset from one another. It is conceivable here that the flexible elements are offset from one another horizontally and/or vertically from one another, i.e. not directly opposite one another in mirror symmetry. Preferably, the flexible elements each comprise bulges which serve to produce a contact point or a contact surface when a MEMS module approaches an adjacent MEMS module, for example caused by a temperature change. The flexible elements can be dimensioned and positioned such that, with such an approach, the bulge of a flexible element of a MEMS module meets a static area of the adjacent MEMS module. A static area is an area of a MEMS module, preferably its base plate, which is not part of a flexible element of the MEMS module. Such a design and positioning of flexible elements makes it possible to particularly efficiently counteract thermal stresses that occur due to different expansion coefficients of the materials of MEMS modules and the carrier substrate without endangering the structural integrity of the microelectromechanical elements of the MEMS modules.

According to a second aspect of the invention, an illumination optics for a microelectromechanical device for guiding illumination radiation to an object field is proposed, which comprises at least one microelectromechanical device according to the invention, each of the plurality of microelectromechanical components having a mirror element with a reflection surface and a displacement device for displacing the mirror element of the respective one microelectromechanical component, wherein the one or more ASICs are designed to control the displacement devices. An illumination optics according to the invention therefore uses a microelectromechanical device according to the invention as a micromirror array. In particular, it can also include several such micromirror arrays according to the invention, for example in order to implement a larger overall micromirror array with an arrangement of this large number of micromirror arrays, which makes it possible to redirect incident light beams with a larger beam diameter.

According to a third aspect, an illumination system for a projection exposure system is also proposed, which comprises illumination optics according to the invention and a radiation source, in particular an EUV radiation source.

According to a fourth aspect, a projection exposure system for microlithography is proposed, which comprises illumination optics according to the invention and projection optics for projecting a reticle arranged in an object field into an image field.

An illumination optics according to the invention, an illumination system according to the invention and a projection exposure system according to the invention can be part of an EUV lithography system. For such purposes, adjustable optical paths up to a photomask (also referred to as a reticle) are advantageous, which can be implemented in the optical path by a micromirror array as a microelectromechanical device according to the invention. The reflection surfaces of the mirror elements can be provided with a Bragg coating, which reflects the central wavelengths of the light used for exposure particularly well.

For further details regarding the general structure of a corresponding projection area lighting system and associated lighting optics and an associated lighting system are on the DE 10 2015 204 874 A1 and the DE 10 2016 213 026 A1 referred to, which are hereby fully integrated into this application as part of the present application.

According to a fifth aspect of the invention, a method for producing a microelectromechanical device, preferably according to the first aspect of the invention, comprising a carrier substrate and a plurality of MEMS modules is provided. Each of the MEMS modules includes an ASIC layer with one or more ASICs (and optionally other elements such as one or more interposers) and an ASIC layer front and an ASIC layer back, a base plate with a base plate front and a base plate back and comprises a plurality of microelectromechanical components, wherein the base plate is arranged on the ASIC layer front side and the base plate back is connected to the ASIC layer front side. According to the method according to the invention, a MEMS substrate with structures for the microelectromechanical components and the base plates of the several MEMS modules is provided. Such a substrate is typically in the form of a wafer (MEMS wafer) and can be produced, for example, using a method as in DE10 2015 206 996 A1 described, an ASIC substrate with structures for the ASIC layers of the microelectromechanical device is also provided, also typically in the form of a wafer (ASIC wafer). From these two substrates, a coupled substrate, typically in the form of a coupled wafer, is produced by connecting (in the case of wafers: wafer bonding), in particular cohesive connecting (for example soldering, sintering, for example with a silver sintering paste, or eutectic bonding), whereby for Each of the several MEMS modules has several associated electrical contacts formed between the MEMS substrate and the ASIC substrate. This coupled substrate is then separated along predetermined dividing lines, for example along a lattice structure, in order to obtain the multiple MEMS modules. Furthermore, a carrier substrate is provided, on which further electronics can optionally be attached. The multiple MEMS modules are placed on a substrate surface of the carrier substrate. The ASIC layer backsides of the several MEMS modules are then materially connected, for example by soldering or sintering, for example with a silver sintering paste, to the substrate surface. This method is preferably carried out to produce a microelectromechanical device whose MEMS modules include handling areas for placing the MEMS modules on the substrate surface of the carrier substrate. This allows the MEMS modules to be easily placed on the substrate surface without having to limit the fill factor. Also preferably, before producing the coupled substrate, testing of the microelectromechanical structures of the MEMS substrate and/or testing of the ASIC structures of the ASIC substrate is carried out to ensure functionality. To ensure functionality, testing of the MEMS modules can preferably also be carried out after the coupled substrate and/or the entire completed microelectromechanical device has been produced after the backsides of the ASIC layer of the several MEMS modules have been cohesively connected to the substrate surface.

Advantages of the invention

The invention offers an approach for microelectromechanical devices such as micromirror arrays that include a plurality of microelectromechanical components arranged on the same carrier substrate when the thermal expansion coefficients of the carrier substrate differ from that of the microelectromechanical components. The approach according to the invention counteracts harmful thermal stresses due to this difference. At the same time, the various embodiments according to the invention can ensure a high filling factor through the microelectromechanical elements.

By structuring the microelectromechanical components according to the invention into individual smaller units (MEMS modules), thermal stresses that are frozen in particular during the production process can be reduced. At the same time, by using action areas and flexible elements between the microelectromechanical components, a high fill factor can be achieved by the MEMS modules and thus also the microelectromechanical components despite this separation. A microelectromechanical device according to the invention is therefore particularly suitable for applications in which high precision and a high fill factor are important, for example in special optics such as for EUV lithography.

Brief description of the drawings

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

• 1 eine schematische Darstellung eines Teils einer beispielhaften erfindungsgemäßen mikroelektromechanischen Vorrichtung in einer Seitenansicht;
• 2A eine schematische Darstellung eines Teils einer zweiten beispielhaften erfindungsgemäßen mikroelektromechanischen Vorrichtung mit Handhabungsbereichen in einer Draufsicht;
• 2B eine schematische Darstellung eines Teils einer Variante der zweiten beispielhaften erfindungsgemäßen mikroelektromechanischen Vorrichtung mit anderen Handhabungsbereichen in einer Draufsicht;
• 3 eine schematische Darstellung eines Teils einer dritten beispielhaften erfindungsgemäßen mikroelektromechanischen Vorrichtung mit flexiblen Elementen in einer Seitenansicht und einer Draufsicht; und
• 4 in schematischer Form als Flussdiagramm ein erfindungsgemäßes Verfahren zur Herstellung einer mikroelektromechanischen Vorrichtung.

Show it:

• 1 a schematic representation of a part of an exemplary microelectromechanical device according to the invention in a side view;
• 2A a schematic representation of a part of a second exemplary microelectromechanical device according to the invention with handling areas in a top view;
• 2 B a schematic representation of a part of a variant of the second exemplary microelectromechanical device according to the invention with other handling areas in a top view;
• 3 a schematic representation of a part of a third exemplary microelectromechanical device according to the invention with flexible elements in a side view and a top view; and
• 4 in schematic form as a flow chart a method according to the invention for producing a microelectromechanical device.

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are referred to with the same reference numerals, with a repeated description of these elements being omitted in individual cases. For the sake of clarity, if there are a large number of identical or similar elements, only a purely exemplary selection of these elements is provided with reference symbols if the equality or similarity of these elements is apparent from the figures and/or the description of the figures. The figures represent the subject matter of the invention only schematically.

1 shows a schematic representation of part of an exemplary microelectromechanical device 110 according to the invention, a micromirror array, in a side view. In the example shown, two MEMS modules 120 are arranged on the substrate surface 100a of a carrier substrate 100, each comprising several microelectromechanical components 130, of which in the 1 four each are shown. In the case shown, the microelectromechanical components 130 are micromirrors. These each include a mirror element 134, which in turn has a reflection surface 136 for reflecting light. These mirror elements 134 can be moved by displacement devices 132. ASICs are used to control the displacement devices, which are arranged in the form of dies below the displacement devices in ASIC layers 140 and are also part of the respective MEMS module 120. Further electronics, for example also for controlling the displacement devices, for example in the form of further ASICs, can be arranged, for example, on the back 100b of the carrier substrate 100 (not shown).

Within a MEMS module 120, the microelectromechanical components 130 are arranged on the front side 160a of a base plate 160. This base plate front side 160a is connected to the back sides 130b of the microelectromechanical components 130. In the example shown, two base plates 160 are visible, on which the four microelectromechanical components 130 shown are located. The microelectromechanical components 130 are connected to the ASICs of the respective ASIC layer 140 via electrical contacts 144. The ASICs of the ASIC layers 140 can in turn be connected to further electronics (not shown) via electrical contacts 146, which can be arranged on the carrier substrate 100, for example. For example, silicon vias (TSV, through-silicon via) 142 can also exist in the ASIC layers 140, which can be used, for example, to produce electrical connections between such further electronics on the carrier substrate 100 and the microelectromechanical components 130. Such vias 142 can be implemented, for example, by means of interposers, which can also be part of the ASIC layers 140, or by means of the dies of the ASICs.

The MEMS modules 120 shown each have flexible elements 150. The flexible element 150a of the left MEMS module 120a is arranged adjacent to the right MEMS module 120b, i.e. is oriented towards it. The flexible element 150b of the right MEMS module 120b is oriented away from the first MEMS module 120a. Here, the flexible elements 150 are implemented as part of an area of the base plates 160. More specifically, the flexible elements 150 shown each extend over part of the side surface of the base plates 160 of the MEMS modules 120; the upper regions 165 of the base plates 160 are not used for the flexible elements 150.

Furthermore, in the 1 Two handling areas 180 per MEMS module 120 are visible, which are located on two of the four microelectromechanical components 130. In the case shown, the handling areas 180 are areas that can be realized, for example, by grooved lateral edges 190 of the microelectromechanical components 130. Using a suitable vacuum based handling device can It may be advantageous if a MEMS module 120 is at least partially delimited to the outside by a frame 170 in order to simplify the production of a negative pressure in the delimited area. At the same time, such a frame 170 can serve to protect the MEMS modules 120 from dirt particles. For clarity, the course of these edges 190 is shown in dashed lines without a groove. By means of these handling areas 180, the MEMS modules 120 can be placed on the carrier substrate 100 without risking damage to the MEMS modules 120 and in particular their microelectromechanical components 130 with the sensitive reflection surfaces 136.

2A shows a schematic representation of a part of a second exemplary microelectromechanical device 210 according to the invention in a top view comprising four mutually adjacent MEMS modules 220a, 220b, 220c, 220d with handling areas 280a, 280b, 280c, 280d. The four MEMS modules 220 each have 16 microelectromechanical components 230 and have four handling areas 280. These handling areas 280 are realized by grooved lateral edges 290 of the MEMS modules 220. Here, the side edges 290 correspond to the corners of the base areas of the MEMS modules, with the course of the square base areas in the area of the handling areas being illustrated by dashed lines. The microelectromechanical device 210 in the 2A does not show any flexible areas, but these are conceivable. It is also conceivable that the handling areas 280 have a different shape than that shown, for example an angular shape, for examples of this see 2 B referred. Since the MEMS modules 280 meet in the middle, the four handling areas 280 located there form a circular recess. A handling device with a manipulator that is cylindrically shaped according to the recess can use such a manipulator to arrange all four MEMS modules in a defined manner relative to one another. A handling device can therefore be designed in such a way that a MEMS module is automatically arranged to match neighboring MEMS modules when it is placed by such a handling device. Furthermore, frames 270 (solid lines) can protect the MEMS modules 280 from dirt particles and/or assist in generating a negative pressure when gripping the MEMS modules by means of a corresponding handling device that generates negative pressure.

2 B is a modification of the 2A and shows other options for implementing handling areas 280 using four additional adjacent MEMS modules 220e, 220f, 220g, 220h. The handling areas 280e of the MEMS module 220e are implemented as rectangular recesses (also grooves in the sense of this invention) of the side edges 290. The MEMS module 220f, on the other hand, uses beveled side edges 290. The neighboring MEMS modules 220g and 220h finally use centrally placed, semicircular recesses in the side surfaces of the MEMS modules. As shown, in the MEMS modules 220g and 220h, the semicircular recesses 280g, 280h on the adjacent side surfaces complement each other to form a circle. Similar to handling areas 280a, 280b, 280c, 280d, 280e, 280f arranged in the corners, lateral handling areas 280g, 280h enable a suitable handling device to arrange the MEMS modules 220 in a defined manner relative to one another. Instead of semicircular recesses as handling areas 280g, 280h, other shapes such as rectangular recesses are also conceivable.

3 Finally, in an upper partial figure A shows a schematic representation of a part of a third exemplary microelectromechanical device 310 according to the invention with flexible elements 350 in a top view, with two adjacent MEMS modules 320 being shown. Furthermore, the shows 3 in a partial figure B a schematic representation of a part 320s of the left MEMS module 320a from partial figure A in a side view. For the sake of clarity, the ASIC layer of the MEMS module 320a and the carrier substrate on whose surface the MEMS module 320a is arranged are not shown in part B for the sake of clarity.

In the microelectromechanical device 310 shown, the flexible elements 350 are realized by recesses 354 in the base plate 360 and consist of a web with an external vertical bulge 352, the web being part of a side surface of the base plate 360 of the corresponding MEMS module 320. The MEMS modules 320 each consist of 16 microelectromechanical components 330, with the position of the underlying recesses 354 in the upper part of figure A being marked as dashed lines for illustration. As shown in partial figure B, the flexible elements 350 do not extend over the full height of the side surface of the respective base plate 360, instead the side surface of a certain area 365 of the base plate 360 is not occupied by flexible elements 350 in order to ensure a stable arrangement of all microelectromechanical components 330 on the To enable top 360a of the base plate 360. In partial figure B, the extent of the flexible elements 350 is also indicated by dashed lines 356. In order to ensure sufficient mobility of the flexible elements 350, The flexible elements 350 can be at least partially spaced from the area 365 as shown (recesses 358).

The flexible elements 350 of the illustrated left MEMS module 320a and the adjacent right MEMS module 230b are arranged in the respective base plates 360 of the two MEMS modules 320 so that they are offset from one another. Here, the flexible elements of the right side surface of the left MEMS module 320a and the flexible elements of the left side surface of the right MEMS module 320b are dimensioned and positioned so that when the left MEMS module 320a approaches the right MEMS module 320b, like it can be done, for example, by a change in temperature, the bulges 352a of the flexible elements of the right side surface of the left MEMS module 320a meet static areas of the right MEMS module 320b. Conversely, the bulges 352b of the flexible elements of the left side surface of the right MEMS module 320b meet static areas of the left MEMS module 230a. Here, a static area means a part of the base plate 360 that is not part of a flexible element. The arrangement of the flexible elements 352a, 352b shown counteracts thermal stresses due to different materials of MEMS modules 320a, 320b and the carrier substrate without endangering the microelectromechanical components 330.

4 Finally, in schematic form as a flow chart, a method according to the invention for producing a microelectromechanical device 110, 210, 310 comprising a carrier substrate 100 and a plurality of MEMS modules 120, 220, 320, wherein each of the MEMS modules 120, 220, 320 has an ASIC layer 140 comprising one or more ASICs with an ASIC layer front side 140a and an ASIC layer back side 140b, a base plate 160, 360 with a base plate front side 160a, 360a and a base plate back side 160b and a plurality of microelectromechanical components 130, 230, 330, wherein the base plate 160, 360 is arranged on the ASIC layer front side 140a and the base plate back 160b is connected to the ASIC layer front side 140a. This involves providing 410 of a MEMS substrate with structures for the microelectromechanical components 130, 230, 330 and the base plates 160, 360 of the several MEMS modules 110, 210, 310. Likewise, an ASIC substrate is provided 420 with structures for the ASIC layers 140 of the several MEMS modules 120, 220, 320. From these, a coupled substrate is produced by material connection, for example soldering, sintering or eutectic bonding, with several assigned for each of the several MEMS modules 120, 220, 320 electrical contacts 144 are formed between the MEMS substrate and the ASIC substrate. This coupled substrate is then separated along predetermined dividing lines, such as a lattice structure, to obtain the multiple MEMS modules. Furthermore, a carrier substrate 100 is provided, on which additional electronics and/or other components can optionally be attached. The multiple MEMS modules 120, 220, 320 are placed on the substrate surface 100a of the carrier substrate 100. Finally, the ASIC layer backsides 140b of the several MEMS modules 120, 220, 320 are materially connected to the substrate surface 100a in step 470.

This method is preferably carried out to produce a microelectromechanical device 110, 210, 310, whose MEMS modules 120, 220, 320 include handling areas 180, 280 for placing the MEMS modules 120, 220, 320 on a substrate surface 100a of the carrier substrate 100. This enables the MEMS modules 120, 220, 320 to be easily placed on the substrate surface 100a without having to seriously restrict the fill factor with respect to the MEMS modules 120, 220, 320. Also preferably, before producing the coupled substrate, testing 415 of the microelectromechanical structures of the MEMS substrate and/or testing 425 of the ASIC structures of the ASIC substrate is carried out to ensure functionality. Additionally or alternatively, to ensure functionality, testing 445 of the MEMS modules 120, 220, 320 after producing the coupled substrate and/or testing 475 of the entire completed microelectromechanical device 110, 210, 310 after the ASIC has been firmly connected can also be carried out. Layer backsides 140b of the several MEMS modules 120, 220, 320 are made with the substrate surface 100a.

The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, within the range specified by the claims, a large number of modifications are possible, which are within the scope of professional action.

QUOTES INCLUDED IN THE DESCRIPTION

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

Cited patent literature

• DE 102013208446 A1 [0002]
• EP 0877272 A1 [0002]
• WO 2010049076 A2 [0002]
• DE 102013206529 A1 [0002, 0007]
• DE 102013206531 A1 [0002]
• DE 102015204874 A1 [0002, 0007, 0021]
• DE 10213206531 A1 [0007]
• DE 102016213026 A1 [0021]
• DE 102015206996 A1 [0022]

Claims (15)

Microelectromechanical device (110, 210, 310) comprising a carrier substrate (100) with a substrate surface (100a) and several MEMS modules (120, 220, 320), wherein each of the plurality of MEMS modules (120, 220, 320) has an ASIC layer (140) with an ASIC layer front side (140a) and an ASIC layer back side (140b), a base plate (160, 360). a base plate front side (160a, 360a) and a base plate back side (160b) and a plurality of microelectromechanical components (130, 230, 330) with a component back side (130b), wherein the base plate (160, 360) is arranged on the ASIC layer front side (140a) and the base plate back side (160b) is connected to the ASIC layer front side (140a) and the plurality of microelectromechanical components (130, 230, 330). the front of the base plate (160a, 360a) and the backs of the components (130b) are connected to the front of the base plate (160a, 360a), wherein the ASIC layer (140) has one or more ASICs for controlling the plurality of microelectromechanical components (130, 230, 330), the one or more ASICs being connected to the microelectromechanical components (130, 230) via electrical contacts (144). are, wherein the plurality of MEMS modules (120, 220, 320) are arranged on the substrate surface (100a) and the ASIC layer backs (140b) of the plurality of MEMS modules (120, 220, 320) are connected to the substrate surface (100a). are. Microelectromechanical device (110, 210, 310). Claim 1 , characterized in that each of the plurality of microelectromechanical components (130, 230, 330) has a mirror element (134) with a reflection surface (136) and a displacement device (132) for displacing the mirror element (134) of the respective microelectromechanical component (130, 230, 330), wherein the one or more ASICs are designed to control the displacement devices (132). Microelectromechanical device (110, 210, 310). Claim 1 or Claim 2 , characterized in that the carrier substrate (100) consists essentially of a first material, preferably comprising a ceramic, and the plurality of MEMS modules (120, 220, 320) consist essentially of a second material, preferably comprising Si, wherein the first material has a first coefficient of thermal expansion α ₁ and the second material has a second coefficient of thermal expansion α ₂ that is different from the first, the first coefficient of thermal expansion α ₁ and the second coefficient of thermal expansion α ₂ preferably having a ratio of α ₁ /α ₂ ≥ 1.5 to one another . Microelectromechanical device (110, 210, 310) according to one of the preceding claims, characterized in that the plurality of MEMS modules (120, 220, 320) have a substantially rectangular, preferably square base area and are arranged in a rectangular, preferably square grid or have a substantially hexagonal base area and are arranged in a hexagonal grid, wherein preferably each of the plurality of MEMS modules (120) has a distance of ≤ 50 µm, preferably ≤ 10 µm, particularly preferably ≤ 10 µm to at least one adjacent MEMS module (120) and particularly preferably to all neighboring MEMS modules (120). Microelectromechanical device (110, 210, 310). Claim 4 , characterized in that each of the plurality of microelectromechanical components (30, 230) of each of the plurality of MEMS modules (120, 220) has a substantially rectangular, preferably square or a substantially hexagonal base area. Microelectromechanical device (110, 210, 310). Claim 5 , characterized in that the MEMS modules (120, 220, 320) each have at least one, preferably at least three, particularly preferably four or more not through the several microelectromechanical components (130, 230, 330) of the MEMS module (120, 220 , 320) include covered handling areas (180) for placing the MEMS modules (120, 220, 320) on the substrate surface (100a). Microelectromechanical device (110, 210, 310), according to Claim 6 , characterized in that each of the at least one handling areas (180, 280) of each MEMS module (120, 220, 320) is characterized by a beveled or a grooved lateral edge (190, 290) or a recess (280h, 280g) of a side surface the plurality of microelectromechanical components (130, 230, 330) of the MEMS module (120, 220, 320) is formed. Microelectromechanical device (110, 210, 310) according to one of Claims 4 until 7 , characterized in that the microelectromechanical device (110, 210, 310) comprises a plurality of flexible elements (150, 350) for reducing mechanical stresses between at least two of the plurality of MEMS modules (120, 220, 320), each of the plurality of flexible Elements (150, 350) Part of a MEMS module (120, 220, 320) of the plurality of MEMS modules (120, 220, 320) and is arranged on and/or in a side surface of this MEMS module (120, 220, 320). Microelectromechanical device (110, 210, 310). Claim 8 , characterized in that each of the plurality of flexible elements (150, 350) is arranged in a side surface of a MEMS module (120, 220, 320) and comprises a web, the web being a part of the side surface of the MEMS module (120, 220, 320) and is formed by a recess (354) of the MEMS module (120, 220, 320), preferably a base plate (160, 360) of the MEMS module (120, 220, 320), and preferably an external one Has bulge (352). Microelectromechanical device according to Claim 8 or 9 , characterized in that each of the plurality of MEMS modules (120, 220, 320) has one or more of the plurality of flexible elements (150, 350), the plurality of MEMS modules (120, 220, 320) being arranged such that the one or more flexible elements (150, 350) of each of the plurality of MEMS modules (120, 220, 320) are each adjacent to another MEMS module (120, 220, 320) of the plurality of MEMS modules (120, 220, 320 ) are arranged. Microelectromechanical device (110, 210, 310) according to one of Claims 8 until 10 , characterized in that a first MEMS module (120a, 320a) of the plurality of MEMS modules (120, 220, 320) has a first base plate (160, 360) with at least a first flexible element (350a) of the plurality of flexible elements (150 , 250) and a second MEMS module (120b, 320b) of the plurality of MEMS modules (120, 220, 320) comprises a second base plate (160, 360) with at least one second flexible element (350b) of the plurality of flexible elements (150 , 250), wherein the first MEMS module (120a, 320a) and the second MEMS module (120b, 320b) are arranged relative to one another such that the at least one first flexible element (350a) is adjacent to the second base plate (160, 360) and the at least second flexible element (350b) are arranged adjacent to the first base plate (160, 360) and are preferably arranged offset from one another. Illumination optics for a projection exposure system for guiding illumination radiation to an object field, comprising one or more microelectromechanical devices (110, 210, 310). Claim 2 and preferably one of the Claims 3 until 11 . Lighting system for a projection exposure system comprising lighting optics Claim 12 and a radiation source, in particular an EUV radiation source. Projection exposure system for microlithography comprising illumination optics Claim 12 and projection optics for projecting a reticle arranged in an object field into an image field. Method for producing a microelectromechanical device (110, 210, 310), preferably according to one of Claims 1 until 11 , comprising a carrier substrate (100) and a plurality of MEMS modules (120, 220, 320), each of the MEMS modules (120, 220, 320) comprising an ASIC layer (140) comprising one or more ASICs with an ASIC layer -Front side (140a) and an ASIC layer back side (140b), a base plate (160, 360) with a base plate front side (160a, 360a) and a base plate back side (160b) and several microelectromechanical components (130, 230, 330), wherein the baseplate (160, 360) is arranged on the ASIC layer front side (140a) and the baseplate backside (160b) is connected to the ASIC layer front side (140a), comprising the following steps: a. Providing (410) a MEMS substrate with structures for the microelectromechanical components (130, 230, 330) and the base plates (160, 360) of the plurality of MEMS modules (110, 210, 310); b. providing (420) an ASIC substrate with structures for the ASIC layers (140) of the plurality of MEMS modules (120, 220, 320); c. Producing (430) a coupled substrate by connecting the MEMS substrate to the ASIC substrate, with multiple associated electrical contacts (144) being formed between the MEMS substrate and the ASIC substrate for each of the plurality of MEMS modules (120, 220, 320). become; d. singulating (440) the coupled substrate along predetermined separation lines to obtain the plurality of MEMS modules (120, 220, 320); e. Providing (450) the carrier substrate (100); f.placing (460) the plurality of MEMS modules (120, 220, 320) on a substrate surface (100a) of the carrier substrate (100); and G. materially connecting (470) the ASIC layer backs (140b) of the several MEMS modules (120, 200) to the substrate surface (100a).

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