METHOD FOR PRODUCING OPTICAL COMPONENTS USING FUNCTIONAL ELEMENTS

Description

Technisches Gebiet

[0001] The invention relates to a method for producing optical components, in particular covers for encapsulating micro-systems, which in particular have to fulfil an optical function.

[0002] A lid for encapsulating microsystems (e.g., MOEMS, MEMS), which are typically arranged on a carrier substrate, should generally provide at least protection against contamination while simultaneously not impairing the mechanical and / or optical functionality of the microsystems. If the functionality of the microsystems is not limited to movements in or parallel to the carrier substrate plane, but also allows for movements perpendicular to the carrier substrate plane, a lid must typically guarantee the microsystems the appropriate freedom of movement. This requires structuring processes that, for example, ensure a high surface quality of the optically functional areas. Stand der Technik

[0003] If the micro-systems are to perform an optical function or if certain parameters or physical quantities of the micro-systems are to be measured optically – for example, determining the deflection using an interferometer or by evaluating video sequences – then an optically transparent cover is usually required. ( Fig. 1a )

[0004] WO 2004 / 1068665 describes a wafer-level packaging process for MOEMS that uses a glass lid. However, before the encapsulation process, the carrier wafer with the MOEMS is separated. The resulting separate bare dies (DIEs) are placed on a new substrate, mounted, contacted, and only then encapsulated. Recesses in the lid can be created using known embossing and etching processes and / or by using spacers, for example, made of silicon.

[0005] US6146917 describes a wafer-level packaging process for MEMS / MOEMS in which a recessed silicon or glass cover wafer is bonded to the carrier wafer by fusion bonding or anodic bonding, resulting in a hermetically sealed package. The required 50 to 150 µm-deep recesses in the silicon cover wafer can be created by wet-chemical etching using a KOH solution.

[0006] US2005 / 0184304 presents a wafer-level packaging process for encapsulating surface-micromechanically manufactured micromirror arrays. A glass cover wafer has recesses that serve as optical windows and can be coated with coatings. The recesses in the cover wafer can have depths of over 100 µm and are created using common forming processes, such as etching, casting, or embossing, or by using spacers.

[0007] What all of the documents cited have in common is that the optical windows of the cover are designed parallel to the substrate plane of the carrier substrate (carrier substrate plane), in particular the carrier wafer, and thus to the MEMS / MOEMS arranged thereon. Furthermore, the prior art describes covers with recesses defined by optical windows inclined to the carrier substrate plane.

[0008] As described in WO2007 / 069165 and US 7,948,667, reflection suppression ( Fig. 1b ) can be achieved.

[0009] According to US2007 / 0024549A1, lids with inclined optical windows can also be manufactured, enabling wafer-level encapsulation. The lid's shape, or the creation of the required recesses, is carried out using conventional embossing and forming processes.

[0010] Such molding processes include, for example, glass deep drawing and glass molding. Bench molding, in particular, is also used to manufacture optical components such as lenses; (see Bernd Bresseler, "Microproduction - Toolmaking as the Measure of Things" on the website http: / / www.aixtooling.de / index.html?content= / deutsch / aktuelles / aktuelles.html and John Deegan Rochester Precision Optics' "Precision Glass Molding Technical Brief" on the website http: / / www.rpoptics.com / Precision%20Glass%20Molding%20Technical%20Brief_2.pdf) .

[0011] Optical components that have flat or plane-parallel surfaces, such as mirrors or partially transparent mirrors and beam splitters (publications by Chuan Pu, Zuhua Zhu and Yu-Hwa Lo "Surface Micromachined Integrated Optic Polarization Beam Splitter"; IEEE PHOTONICS TECHNOLOGY LETTERS, Vol. 10, NO. 7, JULY 1998 and Lih Y. Lin and Evan L. Goldstein "Micro-Electro-Mechanical Systems (MEMS) for WDM Optical-Crossconnect Networks", IEEE 1999) are usually made of silicon in microsystem technology. For example, tilted mirrors can be realized using anisotropic wet-chemical etching processes, for example using KOH (publication Jenq-Yang Chang, Chih-Ming Wang, Chien-Chieh Lee, Hsi-Fu Shih and Mount-Learn Wu "Realization of Free-Space Optical Pickup Head With Stacked Si-Based Phase Elements"; IEEE PHOTONICS TECHNOLOGY LETTERS).

[0012] In the publication "Micromachined Fourier transform spectrometer on silicon optical bench platform"; Sensors and Actuators A130-131 (2006) 523-530 by Kyounggsik Yu, Daesung Lee, Uma Krishnamoorthy, Namkyoo Park, and Olav Solgaard, micro-optical beam splitters and tilted mirrors are also manufactured using various etching processes, highlighting the high quality, particularly low roughness, of the optically functional surfaces. Using wet-chemical KOH etching, surfaces with a root mean square roughness of less than 20 nm can be achieved in silicon. However, such surfaces can only be realized in standard silicon wafers with specific tilt angles determined by the crystal structure of silicon.

[0013] The production of optical components based on glass, such as borosilicate glass, by etching processes usually results in surfaces whose roughness is unsatisfactory for optical applications (see publications Xinghua Li, Takashi Abe, Masayoshi Esashi "Deep reactive ion etching of Pyrex glass using SF6 plasma", Sensors and Actuators A87, 2001, pp. 139-145 and Ciprian Iliescu, Kwong Luck Tan, Francis EH Tay, Jianmin Miao "Deep Wet and Dry Etching of Pyrex Glass: A Review").

[0014] A method for producing optical components, in particular covers with inclined optical windows, is also described in DE102008012384 and WO2013 / 079131. By using reinforcing elements and glass flow, the areas acting as optical windows can be tilted in a protected and stabilized manner, allowing the creation of high-quality inclined and / or shifted optical windows. A disadvantage of the method is that structuring the glass substrates requires a relatively high material expenditure, since different areas of the glass substrate are intended for force absorption, deformation, and the optical windows.

[0015] US 2001 / 0022382 further describes a method for producing a housing for optical applications, wherein a frame-shaped solder layer is applied by deposition processes to achieve the inclination of the optical window.

[0016] US 2013 / 0285169 discloses a method for producing a cover with an optical window for encapsulating MEMS, wherein a deformable layer made of a transparent material is used and the inclination of a displaceable region is effected by deforming a region of the deformable layer that defines an inclination axis.

[0017] In addition, EP 0 709 881 discloses, in connection with the hermetic encapsulation of semiconductors, a frame-shaped preform which is deformed during the encapsulation process. Beschreibung

[0018] The present invention is therefore based on the object of overcoming the disadvantages of the prior art and providing a cost-effective and more flexible method for producing optical components, in particular covers, with shifted and / or inclined regions and high surface quality.

[0019] According to the present invention, this object is achieved by a method according to claim 1 for producing optical components, in particular a cover. The subclaims teach advantageous further developments.

[0020] The inventive method according to claim 1 serves to produce optical components in which one or more regions or surfaces, in particular surfaces, that must fulfill an optical function are inclined and / or shifted with respect to a reference region or a reference surface of the manufactured optical component or a component used in the application for which the optical component is intended, wherein the reference region or the reference surface must also fulfill an optical function. In particular, the inventive method is applicable at the wafer level, whereby several optical components can be produced in parallel.

[0021] The optical component comprises in particular at least one optical element such as an optical window, a mirror or partially transparent mirror, a beam splitter, a prism, a lens and / or an interference filter, or the optical component consists of at least one optical element.

[0022] The surfaces of an optical window through which the radiation used in the application enters the optical window and / or is coupled out again represent the transmission surfaces of an optical window.

[0023] The method according to the invention can be used, for example, to produce a lid with one or more optical windows for encapsulating microsystems, which in particular must fulfill an optical function and are usually applied or arranged on a carrier substrate. A silicon wafer is often used as the carrier substrate, on which the microsystems to be encapsulated (e.g., MEMS, MOEMS) are produced using surface micromechanical or bulk micromechanical processes.

[0024] The method according to the invention according to claim 1 for producing one or more optical components, in particular micro-optical components, comprises the method steps listed in claim 1, including: Providing a deformation element that contains or consists of glass and / or a glass-like material at least in one region, and a carrier, bringing the deformation element into contact with the carrier, thereby forming a first contact surface between the deformation element and the carrier, applying a functional element to the deformation element such that a second contact surface is formed between the functional element and the deformation element, which second contact surface at least partially overlaps the first contact surface, so that a deformation region is formed by the region of the deformation element that is formed between the overlapping regions of the two contact surfaces, heating and deforming at least a part of the deformation region such that the functional element shifts and / or inclines at least partially in relation to the carrier,Connecting the functional element to the deformation element during the method step of applying the functional element to the deformation element and / or during the method step of heating and deforming the deformation region, wherein the deformation element is a wafer or the deformation element is provided by separating and / or structuring a wafer and wherein the deformation region is frame-shaped and / or at least two deformation regions are formed which are in contact with the same functional element, and / or the overlapping region of the second contact surface corresponds approximately to the second contact surface.

[0025] The deformation element is a central element for the production of the optical component. By deforming the deformation element or the deformation region, the orientation or position of the functional element can be changed compared to its initial position or in relation to the carrier without the functional element being subjected to deformation. This can, for example, maintain a high optical quality of the functional element. The deflection of the functional element is at least partially determined by the deformation of the deformation element or the deformation region, and not just by a change in the position of the entire deformation element and / or the carrier.

[0026] In addition, by deforming the deformation element, its initial shape can be specifically modified and brought into a desired final shape.

[0027] The deformation element is in particular a substrate, whereby a plurality of optical components can be produced in parallel, or a structural element, whereby deformation elements with special geometries, for example in the form of a frame (frame-shaped structure), can be provided.

[0028] Many optical components should be transparent to the electromagnetic radiation used in the application, usually in their entirety, at least in certain areas. Most optical applications require the highest possible transparency of the areas that are to be transparent to the electromagnetic radiation used in the application, so that, for example, a laser beam reaches the microsystem with as little influence as possible.

[0029] Accordingly, the deformation element contains glass and / or a glass-like material in at least one region, or the deformation element consists of glass and / or a glass-like material. For the purposes of the invention, glass-like materials are understood to be substances that resemble glasses due to their thermodynamic properties (amorphous structure, glass transition temperature), although their chemical composition differs from that of silicate glasses. Examples include artificial glasses or organic vitroids known in chemistry, such as polymethyl methacrylate (PMMA), polycarbonate, and polystyrene.

[0030] Suitable glasses include silicate glasses, especially borosilicate glasses, as borosilicate glasses are highly chemical and temperature-resistant. The temperature resistance and insensitivity of borosilicate glasses to sudden temperature fluctuations are a result of their low coefficient of thermal expansion. Furthermore, the transmittance is very high, at over 90%, especially in the wavelength range visible to humans.

[0031] In addition to one or more deformation elements, at least one carrier is provided which supports the deformation element at least in part and ensures stable force absorption, in particular during heating and deformation.

[0032] The carrier is in particular a substrate, preferably a silicon wafer, or another flat support (for example a tool or a table top) which can accommodate one or more deformation elements and thus enables optimized serial and / or parallel processing, whereby the efficiency of the manufacturing process can be increased.

[0033] The carrier preferably contains a semiconducting material in at least one region, or the carrier consists of a semiconducting material, in particular silicon. Thus, semiconductor wafers, for example silicon wafers, can be used as carriers, allowing the use of sophisticated and easily controllable processes of semiconductor technology, in particular silicon technology.

[0034] The carrier—in particular one or more regions of the carrier that are brought into contact with the deformation element—in particular comprises a non-stick coating, which in particular contains a silicate and aluminum hydroxide, and / or the carrier is coated with or contains in particular high-temperature-resistant materials, in particular graphite, titanium aluminum nitride, boron nitride, silicon carbide, a precious metal, in particular platinum, and / or a precious metal alloy, in particular a platinum-indium or a platinum-iridium alloy, or the carrier or the region consists thereof. Due to their low tendency to bond with the deformation element, in particular with glass, and the resulting low wear, such carriers can be used multiple times or over a longer period of time (longer service life).

[0035] In a further embodiment, the carrier has a support structure which limits the deflectability and / or deformability of at least one region of the functional element and / or at least one region of the deformation element in such a way that tilting of the functional element is supported or achieved. This ensures targeted or differentiated force absorption and thus optimizes the process, in particular with regard to the manufacturing time and the reproducibility of the optical component. In particular, when the support structure comes into contact with the functional element, forces acting on the functional element can be directly absorbed by the support structure or the carrier, thus specifically relieving the load on regions of the deformation region.

[0036] In a further method step, the deformation element is brought into contact with the carrier, whereby at least a first contact surface is formed between the deformation element and the carrier.

[0037] Furthermore, the functional element is applied to the deformation element in such a way that at least one second contact surface is formed between the functional element and the deformation element, which second contact surface at least partially overlaps the first contact surface, so that at least one deformation region is formed by the region of the deformation element which is formed between the overlapping regions of the two contact surfaces.

[0038] Regarding the chronology of these two process steps, it is possible to bring the deformation element into contact with the substrate before or after the functional element is / has been applied to the deformation element. Alternatively, simultaneous processing can take place.

[0039] The functional element is a further basic element for the production of the optical component, whereby the functional element can ultimately be a component of the produced optical component and in particular can have an optical functionality.

[0040] Furthermore, the functional element can protect the deformation element or one or more surface areas of the deformation element from excessive mechanical stress or from direct contact with the forming device when using forming devices (e.g. stamps) and / or can transmit or distribute an externally applied force, for example based on a pressure difference, to the deformation area.

[0041] In addition, the functional element can be used as a molding element, whereby one or more surface areas of the functional element are molded onto the deformation element or onto one or more surface areas of the deformation element. For example, structures or properties of a surface area of the functional element, such as roughness and / or flatness, can be transferred to the deformation element.

[0042] The functional element is, in particular, an optical element, for example, an optical window, a mirror, a partially transmissive mirror, a beam splitter, a prism, a lens, and / or an interference filter. Such an optical element can, for example, be manufactured separately prior to the process and then integrated into the optical component to be manufactured as part of the process. The separation between the manufacturing and integration of the optical element enables at least partially independent optimization of both processes and a high quality of the optical component, in particular by maintaining the optical quality of the optical element.

[0043] To ensure high quality of the optical component, in particular of the surfaces, at least one region of the surface of the functional element, in particular a region intended to function as a transmission surface and / or to be brought into contact with the deformation element, has, in particular, a root mean square surface roughness of less than or equal to 25 nm, preferably less than or equal to 15 nm, particularly preferably less than or equal to 5 nm and / or, in particular, a flatness deviation per measured length (relative flatness deviation) of less than or equal to 180 nm / mm, preferably less than or equal to 100 nm / mm. This can be achieved, for example, by polishing the region.

[0044] Preferably, the functional element is an optical window with at least two transmission surfaces, wherein the transmission surfaces are flat (planar) and / or parallel to one another.

[0045] To meet optical quality requirements, the transmission surfaces preferably have a relative flatness deviation of less than or equal to a quarter of the wavelength of the electromagnetic radiation used in the application per millimeter, with wavelengths from the ultraviolet to the infrared wavelength range (for example, between approximately 200 nm and approximately 15 µm) being particularly preferred. To cover a broad range of applications, the transmission surfaces preferably have a relative flatness deviation of less than or equal to 180 nm / mm, particularly preferably less than or equal to 100 nm / mm.

[0046] In addition, the transmission surfaces preferably exhibit a plane-parallelism deviation per measured length (relative plane-parallelism deviation) of less than or equal to 10 µm / mm. With such surface properties, the functional element, in particular the optical window, offers optimal conditions for an optical component (e.g., a cover) that causes smaller deviations and less beam expansion of the optical beam path, thus leading to less distortion of the optical signals.

[0047] The values for flatness and plane-parallelism deviation, as well as for root-mean-square surface roughness, were determined using interferometric measurement methods. The MicroMap 512 white-light and phase interferometer from Atos or the VEECO Wyko NT 1100 from Veeco were used for the measurements.

[0048] Furthermore, the functional element should preferably have a homogeneous material structure to avoid unwanted refractions and / or deflections of the radiation.

[0049] A plurality of optical components should be permeable to the electromagnetic radiation used in the application, at least in one area, particularly in their entirety. Accordingly, the functional element contains glass and / or a glass-like material, in particular at least in one area, or the functional element is made of glass and / or a glass-like material.

[0050] Suitable glasses include silicate glasses (e.g., borosilicate glass) with and without alkaline earth metal additives, such as Eagle XG ® (Corning), Hoya SD 2 ® (Hoya), and AF 32 ® (Schott), as these glasses are highly chemical and temperature resistant. The temperature resistance and insensitivity of these glasses to sudden temperature fluctuations are a result of their low coefficient of thermal expansion. Furthermore, the transmittance is very high, at over 90%, especially in the wavelength range visible to the human eye.

[0051] In a further embodiment, the functional element contains a semiconducting material, in particular silicon, at least in one region, or the functional element is made of such a material, which allows the use of sophisticated and easily controllable processes of semiconductor technology, in particular silicon technology. Furthermore, silicon, in particular, has a transmittance of over 90% for infrared radiation with suitable anti-reflective coating.

[0052] Particularly suitable materials for the functional element have a thermal expansion coefficient that is as close as possible to, or as identical to, the thermal expansion coefficient of the material of the deformation element. Preferably, the difference between the thermal expansion coefficient of the material of the deformation element and the thermal expansion coefficient of the material of the functional element should be less than or equal to 5 ppm / °K, particularly preferably less than or equal to 1 ppm / °K. This makes it possible to reduce mechanical stresses that can arise during cooling due to different contractions of the material of the deformation element or the deformation region and the material of the functional element, and which could lead to damage to the deformation element and / or the functional element or the optical component.

[0053] When bringing the deformation element into contact with the carrier and / or when applying the functional element to the deformation element, the deformation element and the carrier or the functional element and the deformation element are preferably connected to one another, particularly preferably in a form-fitting and / or material-fitting manner, in particular by gluing, soldering or bonding, in order to ensure high positional stability of the deformation element with respect to the carrier and / or of the functional element with respect to the deformation element.

[0054] In a preferred embodiment, a positive connection between the functional element and the deformation element is achieved by arranging the functional element in an adjustment recess of the deformation element, which is designed to accommodate the functional element. Equivalently, a positive connection can be established between the deformation element and the carrier by arranging the deformation element in a specially designed adjustment recess of the carrier. This type of arrangement requires no additional connecting substances (e.g., adhesive) or special connecting steps (e.g., bonding), which could impair the surface quality, in particular of the functional element and / or the deformation element.

[0055] In a further embodiment, the deformation element is brought into contact with the carrier and / or the functional element is applied to the deformation element by anodic bonding, direct bonding, fusion bonding, plasma-activated bonding, and / or thermal bonding. These bonding processes are frequently used joining techniques, particularly in the semiconductor industry, and result in stable connections. Such a joining step is carried out in particular in a vacuum, which allows, for example, air pockets and / or trapped particles in the joining regions, in particular at the interface between the deformation element and the carrier and / or the deformation element and the functional element, and thus resulting defects, in particular in the interface regions of the functional element and / or the deformation element, to be reduced.

[0056] When applying the functional element to the deformation element, the functional element is preferably separated from a functional substrate or cut out of a functional substrate and in particular subsequently brought into contact with the deformation element or arranged on it and in particular connected to it.

[0057] The functional substrate is designed, in particular, as a plate or wafer, for example, a silicon or glass wafer. This allows a multitude of functional elements to be manufactured from one or more functional substrates, and the processing steps can be reduced or optimized, for example, to ensure the desired strength or thickness of the functional elements.

[0058] Preferred separation processes are drilling, sawing, milling, laser cutting or laser machining, breaking (possibly with prior scoring), sandblasting and / or etching.

[0059] By conducting a manufacturing process prior to arranging the functional element on the deformation element, the starting material (functional substrate) for the functional element can be used more effectively. This, along with the associated savings in additional process steps such as paint application, exposure, paint structuring, and paint removal, reduces manufacturing costs.

[0060] The production of functional elements prior to assembly on the deformation element also has the advantage that functional elements made of different materials (e.g., from multiple functional substrates) and with different sizes (e.g., thicknesses) or shapes, as well as with different properties (e.g., transparency, reflectivity, or absorption behavior), can be provided for the subsequent assembly step. This enables optimized and flexible adaptation of production to the desired specifications.

[0061] Furthermore, when manufacturing the functional element before arranging it on the deformation element, the area of the deformation element that is not to be brought into contact or connected with the functional element is exposed to a lesser extent to aggressive media such as etching solutions, so that a high surface quality of this area can be better maintained and preserved for later contacting and / or connecting steps.

[0062] In addition, more complex functional elements or functional elements manufactured using special manufacturing processes (e.g. lenses, prisms) can be used.

[0063] The arrangement of the functional element on the deformation element can be carried out, for example, with a vacuum handler (vacuum suction cup), a gripper (collet) or a pickup tool (combination of vacuum suction cup and gripper), which ensure a positionally accurate and precise arrangement of the deformation element or the functional element.

[0064] In a further embodiment, the at least one functional element is placed on a positioning means before being arranged on the deformation element. The loading of the positioning means, i.e., the transfer and placement of the functional element on the positioning means, can be carried out, for example, using a vacuum handler (vacuum suction cup), a gripper (collet), or a pickup tool (a combination of vacuum suction cup and gripper), which ensure accurate and precise loading on the positioning means.

[0065] Any device, device, or tool that stabilizes or adjusts the functional element in its position is suitable as positioning tools. This stabilization significantly simplifies handling during subsequent process steps. For example, assembly can be performed under cleanroom conditions at atmospheric pressure, while a subsequent bonding step, such as anodic bonding, can be performed in a different cleanroom area under vacuum.

[0066] Suitable positioning agents include, for example, adhesive substrates based on magnetic or electrostatic force or substrates that can ensure force-fitting (e.g. friction-increasing layer), material-fitting (e.g. applied adhesive layer) or form-fitting connections (e.g. depressions or recesses).

[0067] With a view to a subsequent connection step (e.g., anodic bonding), the positioning means is preferably designed to be electrically conductive. Accordingly, the positioning means contains or consists in particular of electrically conductive and / or semiconducting materials, such as silicon.

[0068] A receiving substrate can be used as a suitable positioning means. Such a receiving substrate has at least one recess or depression (receiving depression) designed to accommodate one or more functional elements and, in particular, to hold them laterally fixed or adjusted. Since the adjustment in this case is essentially ensured by a positive connection between the receiving substrate and the functional element, the receiving substrate can be easily removed after the functional element has been arranged on the deformation element by releasing the positive connection in order to release the arrangement thus created for further process steps. The receiving substrate can then be reused for the next assembly process and is thus reusable, which in turn reduces manufacturing effort and costs.

[0069] Additionally or alternatively, the functional element, such as an optical window, can be produced on the deformation element in such a way that at least one functional layer is applied to the deformation element. The functional layer can be produced, for example, by means of deposition processes and / or by using a functional substrate (e.g., a silicon wafer or a glass substrate). The functional layer is preferably bonded to the deformation element, in particular by means of a material bond (e.g., by bonding, soldering, gluing, or deposition), in order to ensure high positional stability of the functional layer and the functional element produced therefrom.

[0070] The functional layer is expediently applied to the deformation element in such a way that displacement and / or twisting of the functional layer relative to the deformation element is reduced or prevented.

[0071] A polysilicon layer is preferably applied to the deformation element as a functional layer, particularly by means of CVD, in particular hot wire CVD or PECVD, or PVD, in particular sputtering. Since the process temperatures for these deposition processes are below 600°C, in particular between 400°C and 500°C, even more temperature-sensitive deformation elements can be coated. Furthermore, the functional layer can be applied to the deformation element in the form of a functional substrate, for example, a silicon wafer, or bonded to it by anodic bonding and / or thermal bonding. These bonding processes are frequently used joining techniques, resulting in stable connections, especially in the semiconductor industry.

[0072] After the functional layer has been applied, it is structured to produce the at least one functional element, in particular by means of drilling, sawing, milling, laser cutting, breaking, sandblasting and / or etching.

[0073] The at least one functional element produced by separating it from the functional substrate is arranged on the deformation element or connected to it, and / or one or more functional elements are created by structuring the functional layer in such a way that they can be deflected by the subsequent deformation of the deformation region. Furthermore, the arrangement or connection and / or structuring, in particular, shapes the shape of the second contact surface, thus adjusting the overlap area.

[0074] The previously described embodiments for applying the functional element to the deformation element apply equivalently to bringing the deformation element into contact with the carrier. Accordingly, the deformation element can be manufactured prior to contacting (e.g., separated or removed from a deformation substrate) and subsequently arranged on the carrier, and / or the deformation element can be created by applying and structuring a deformation layer on the carrier.

[0075] The use of both a deformation element and a functional element enables independent manufacturing and thus individual adaptation of these elements to the process flow or specifications, particularly for the optical component. This allows surfaces—for example, transmission surfaces—that are no longer accessible or difficult to access for processing (e.g., a polishing step) after heating and deformation, for example, to be realized with a high surface quality during the production of the corresponding element (e.g., the functional element).

[0076] The fact that a first layer, a first region, or a first device is arranged or applied "on" a second layer, a second region, or a second device can mean here and below that the first layer, the first region, or the first device is arranged or applied in direct mechanical and / or electrical contact with the second layer, the second region, or the second device. Furthermore, indirect contact can also be referred to, in which further layers, regions, and / or devices are arranged between the first layer, the first region, or the first device and the second layer, the second region, or the second device.

[0077] In a further embodiment, the functional element, the deformation element, and / or the carrier has one or more recesses and / or openings, which are created in particular by drilling, sawing, milling, laser cutting, sandblasting, and / or etching. According to the invention, a hole also represents an opening.

[0078] After the carrier has been brought into contact with the deformation element and / or the functional element has been applied to the deformation element, the recess and / or opening can create a distance between the carrier and the deformation element, between the functional element and the deformation element, or between the functional element and the carrier in the region of the recess and / or opening in order to prevent contact between the surfaces in this region and thus preserve the surface quality (for example, with regard to roughness) of these surface regions, in particular of the functional element. Such contact could also lead to adhesion of the functional element to the deformation element and / or carrier, or of the deformation element to the carrier, particularly during heating and deformation, and prevent or impede deformation-induced deflection of the functional element.

[0079] In order to ensure that the functional element can be deflected as smoothly as possible due to deformation, the areas of the functional element that are not relevant for the formation of the overlapping areas should preferably not be in direct or indirect contact (for example, due to one or more intermediate layers) with the deformation element and / or the carrier, in particular before the deformation area is deformed, in order to prevent the functional element from adhering to the deformation element and / or the carrier in these areas.

[0080] To reduce the adhesive forces in the event of contact, the surfaces or the corresponding surface regions of the functional element, the deformation element, and / or the carrier can be provided with various coatings and / or prepared using surface modification processes (e.g., nanotexturing). Suitable coating materials include platinum, platinum alloys (e.g., platinum-iridium alloy), NiAlN, graphite, and boron nitride. Furthermore, the recess and / or opening can serve to adjust or influence the deformation resistance of the deformation region. This can be achieved, for example, by the recess and / or opening increasing the surface area of the deformation region or reducing the volume of the regions of the deformation element adjacent to the deformation region that is affected by the deformation.

[0081] As a result, the deformation region in the region of the depression and / or opening is not in contact with a solid (the deformation region has a surface that at least partially delimits the depression and / or opening), or is only in contact to a reduced extent, including in particular highly viscous liquids such as glass. As a result, the forces associated with the structural material displacements that occur during the plastic or viscous deformation of the deformation region upon heating and deformation cannot be absorbed, or can be absorbed to a lesser extent, by the vacuum or the material (for example a gas, a liquid, regions of the deformation element) that borders the deformation region. This leads to a reduction in the volume or area over which the deformation force can be distributed, and thus to a reduction in the deformation resistance.

[0082] In the context of the invention, deformation resistance is understood to mean the resistance that the deformation region offers to the force causing the deformation, i.e., the deformation force (e.g., the inherent weight and / or an externally applied force). The deformation resistance results from the ratio of the deformation force to the resulting deformation rate and is proportional to the viscosity, in particular the dynamic viscosity, and to the area or an imaginary cross-sectional area through the deformation region in which the deformation force acts.

[0083] In a further embodiment, the carrier is brought into contact with the deformation element and / or the functional element is applied to the deformation element in such a way that a cavity is formed between the deformation element and the carrier, between the deformation element and the functional element and / or between the functional element, the deformation element and the carrier through the recess and / or opening, wherein the cavity is in particular hermetically sealed.

[0084] In addition to ensuring a distance between different surface areas bounding the cavity to prevent contact or adhesion of the surface areas, in particular prior to heating and deformation, and / or providing an at least partially enclosed volume for the application in which the optical component is used, a pressure below or above the ambient pressure, in particular atmospheric air pressure, can be generated in the cavity, in particular prior to and / or during heating and deformation. Such a pressure difference between the pressure in the cavity and the ambient pressure can generate a force effect to ensure or promote the deformation process.

[0085] In the event that the ambient pressure or process pressure during the heating and forming process step corresponds to atmospheric air pressure, a pressure of between approximately 15 mbar and approximately 30 mbar (negative pressure) or between approximately 1200 mbar and approximately 1600 mbar (positive pressure) is set in the cavity, for example.

[0086] By using suitable joining techniques, such as bonding, it is possible to create a cavity that is hermetically sealed from the environment. By carrying out the joining process at a specific pressure, this pressure value can be created or adjusted in the cavity. The pressure during the joining process, for example anodic bonding at a temperature of 400°C, is preferably between approximately 10 mbar and approximately 20 mbar or between approximately 800 mbar and approximately 1000 mbar. Since the subsequent heating process typically takes place at significantly higher temperatures than the joining process - for example, the deformation element is brought to a temperature between approximately 700°C and approximately 900°C during the heating and deformation process step - the specified pressure ranges result in pressures of approximately 15 mbar to approximately 30 mbar or approximately 1200 mbar to approximately 1600 mbar in the cavity.

[0087] Since the cavity in this case is hermetically sealed from the environment, the set pressure value is maintained over a longer period of time without any additional energy supply, for example to operate a vacuum pump or pump, and thus in particular for the deformation or shaping process.

[0088] In particular, a force can be applied to the deformation element through the cavity between the deformation element and the carrier, in which a pressure is set that leads to an overpressure or underpressure during heating in relation to the ambient pressure or process pressure, whereby at least one area of the deformation element or the deformation area is deformed and the functional element is thereby deflected. In this case, the functional element is subjected to a force only in the area that is in contact or connected to the deformation area or the deformation element during the deformation process.Other areas of the functional element, for example surface areas delimiting the cavity between the support, the deformation element and the functional element, are not exposed to any force causing the deformation of the deformation area, so that the mechanical stress on these areas is reduced and their shape or surface quality (for example flatness and plane parallelism) can be particularly well maintained.

[0089] By bringing the deformation element into contact with the carrier, the first contact surface or interface between the deformation element and the carrier is formed, and by applying the functional element to the deformation element, the second contact surface or interface between the functional element and the deformation element is formed, wherein the second contact surface at least partially overlaps the first contact surface. The region of the deformation element formed between the overlapping regions of the two contact surfaces forms the deformation region.

[0090] The overlapping regions of the two contact surfaces (overlap regions) comprise in particular the regions of the first and second contact surface whose points can be connected to at least one of their images projected onto the respective other contact surface, which, if the following criteria are met, also belong to the overlap regions like the points themselves, by a connecting line which runs over the full length through the deformation element or through the deformation element and a solid body in contact with it (for example, inclusions) and accordingly not through a depression, opening or hole or a cavity which comprises, for example, a vacuum, a gas or a liquid. A point and its image whose connecting line meets the above criteria are hereinafter referred to as a point / image pair.

[0091] The projection of a point of one contact surface onto the other contact surface is carried out in particular in such a way that the connecting line between the point and its image on the other contact surface describes the shortest connection or the shortest distance between the point and the image (hereinafter referred to as "minimal projection") and / or that the point is mapped onto the other contact surface by means of orthogonal projection.

[0092] If both projections (minimal projection and orthogonal projection) lead to images of a point, or if multiple images exist, and a point results in multiple point / image pairs, then not only the point but also all of its images of the point / image pairs belong to the overlap areas. For example, if two images can be assigned to a point, and the point / image pairs Point / Image1 and Point / Image2 exist, then the point, as well as Image1 and Image2, belong to the overlap areas.

[0093] Exceptions are point / image pairs where the minimal projection of the point creates an image on the edge of the other contact surface. The points and images of such point / image pairs do not belong to the overlap areas. For example, if Point / Image1 and Point / Image2 exist, where Image2 is a minimal projection of the point onto the edge of the other contact surface, only the point and Image1 (according to the point / image pair Point / Image1) belong to the overlap areas.

[0094] In a further embodiment, contact surfaces that only comprise points whose minimal projection results in images that fall on the edge of the other contact surface are not included in the overlapping areas, regardless of the result of the orthogonal projection.

[0095] Within the scope of the invention, the deformation region extends in particular to the region of the deformation element which is delimited by the overlapping regions and traversed by the connecting lines of the point / image pairs belonging to the overlapping regions.

[0096] According to the embodiments of the prior art, the substrate to be deformed has different regions that perform different functions, such as the functional region to be deflected, which typically has to fulfill an optical function (e.g., that of a window) within the scope of the application of the optical component; the support region, which is supported by a carrier and thus enables a relative movement between the support region and the functional region of the substrate to be deformed; and the deformation region, whose change in shape ensures a deflection of the functional region. Since these regions are arranged laterally adjacent according to the prior art, substrates to be deformed with corresponding lateral dimensions are required.

[0097] Due to the inventive arrangement of the deformation region between the functional element and the carrier, several, in particular all, functionalities of the said regions can be concentrated or combined in the deformation region, which results in significant savings in material and thus lower costs, since deformation elements with smaller lateral dimensions are required or more optical components can be produced per lateral extension of the deformation element.

[0098] In a further embodiment, the first and / or second contact surface or the overlapping regions of the first and / or second contact surface and / or the deformation region are designed in the form of a frame or frame-shaped (for example, a contact surface in the form of a circular ring), in particular enclosing and preferably closing the recess and / or opening in the deformation element or the recess and / or opening. The regions of the deformation element that create such frame-shaped, in particular closed, overlapping regions can further serve as connecting surfaces, for example to hermetically seal the recess and / or opening enclosed by the frame-shaped deformation region by connecting the deformation element to one or more encapsulation elements. This allows, for example, MEMS or MOEMS to be encapsulated with the required freedom of movement.A further spatial or material optimization, which can contribute to reducing manufacturing costs, can be achieved by ensuring that the deformation region, in particular the frame-shaped deformation region, at least partially delimits the recess and / or opening in the deformation element or the cavity, in particular between the deformation element and the support and / or between the functional element, the deformation element, and the support. This also results in the deformation region having a surface that, as described, influences the deformation resistance.

[0099] The magnitude of the deformation resistance of the deformation zone is determined, for example, by the material used, the shape or form, and the arrangement of the deformation zone, for example, whether the deformation zone borders a gas or a solid. Geometric asymmetries in the deformation zone can result in asymmetries in the deformation resistance (resistance asymmetry), which can cause mechanical stress distributions in the deformation zone, leading to locally different deformation rates. This can support or achieve deformation-induced tilting of the functional element.

[0100] In a preferred embodiment, at least two segments of the frame-shaped deformation region (frame segments) have different deformation resistances, in particular during heating and deformation, whereby in particular a tilting of the functional element during the heating and deformation process step can be promoted or supported.

[0101] In a further embodiment, two or more deformation regions are formed that are in contact with the same functional element or are formed by the same functional element and are preferably formed diametrically around the recess and / or opening in the deformation element and / or at least partially delimit the recess and / or opening in the deformation element. The resulting spatial or material optimization can contribute to reducing manufacturing costs.

[0102] Preferably, the two deformation regions or a respective sub-region of the two deformation regions (two sub-regions of deformation), in particular during heating and deformation, have deformation resistances of different magnitudes, whereby a tilting of the functional element during the heating and deformation process step can be promoted or supported.

[0103] The two deformation regions may be regions of the same deformation element and separated by at least one region of this deformation element that does not function as a deformation region, or the two deformation regions may be associated with different deformation elements.

[0104] The use of multiple deformation zones in conjunction with a functional element, particularly the use of multiple deformation elements, enables greater flexibility in the process, as the deformation zones or deformation elements can be individually designed. For example, the two deformation zones can have different deformation resistances, for example, by using different materials and / or by designing the two deformation zones with different geometrical configurations to promote or support the tilting of the functional element during the heating and deformation process step (during heating and deformation).

[0105] The structural or geometric considerations with regard to the deformation region relate, within the scope of the invention, in particular to the shape of the deformation region before the shaping of the deformation element or before the process step of deforming the deformation region.

[0106] By specifically designing the deformation area, the type of deflection of the functional element can be specifically influenced and, in particular, tilting of the functional element can be promoted or supported.

[0107] Therefore, in a further embodiment, the frame-shaped deformation region or the two deformation regions are designed such that the surface areas of two cross-sectional areas of the frame-shaped deformation region and / or the surface areas of two cross-sectional areas and / or of two total cross-sectional areas of the two deformation regions, wherein the cross-sectional areas are not assigned to the same deformation region of the two deformation regions, are of different sizes.

[0108] The term "frame surface" used below refers to the surface of the frame-shaped deformation area after abstraction by isolating the deformation area. In this context, isolating is understood to mean the imaginary removal of all elements and areas that do not belong to the frame-shaped deformation area. Accordingly, the frame surface is composed of real surfaces (surfaces) and / or surfaces resulting from the abstraction, which arise by isolating real interfaces (in particular between the deformation area and the support or the functional element) and / or imaginary interfaces (in particular between the deformation area and an adjacent area of the deformation element that does not belong to the deformation area).

[0109] A cross-sectional area of the frame-shaped deformation region comprises, in particular, the set of all points of the frame-shaped deformation region bounded by a plane, closed curve. Starting from a point on the frame surface, the curve describes the shortest connection on the frame surface to the point itself (accordingly, the curve begins and ends at the same point), so that the curve only includes points that belong to the frame-shaped deformation region but not to the frame surface. Accordingly, the points of the curve are the only points on the frame surface that are encompassed by the cross-sectional area.

[0110] And / or the cross-sectional areas of the frame-shaped deformation region to be compared result in particular from a section of the frame-shaped deformation region through a section plane spanned by two orthogonal principal axes of inertia and / or principal volume axes (principal axes of inertia in the case of a fiction of a homogeneous mass distribution) of the frame-shaped deformation region, whereby only the section planes are taken into account which result in two cross-sectional areas as a result of the section and which intersect the two contact surfaces.

[0111] The cross-sectional areas of the two deformation zones to be compared result, in particular, from a section through both deformation zones by a cutting plane on which both volume centers of gravity of the two deformation zones lie and which is oriented such that the two contact surfaces are intersected and the sum of the areas of the two cross-sectional areas is a minimum. If the section results in multiple cutting surfaces for a deformation zone, their areas are added to obtain the area of a resulting cross-sectional area that can be used for comparison.

[0112] A total cross-sectional area is the sum of the cross-sectional areas of the two deformation regions, whereby the cross-sectional areas are formed by a section of the two deformation regions through the previously (above) defined section plane or by one of their images generated by parallel translation of the section plane in the direction of their normal vectors.

[0113] By shifting the section plane or plane in which the cross-sectional area lies in the directions specified by the normal vectors of this plane by infinitesimal distances of equal length, in particular an infinitesimal volume element and thus a segment of the frame-shaped deformation region (frame segment) or a sub-region of a deformation region (deformation sub-region) is defined, whereby when comparing two volume elements, both volume elements are spanned by infinitesimal distances of equal length.

[0114] In a further embodiment, the deformation region has a surface, wherein in particular the two segments of the frame-shaped deformation region and / or the two deformation regions and / or the two deformation sub-regions have surfaces with different surface areas.

[0115] The surface of the deformation region can be created or enlarged by structuring the deformation element, in particular by sawing and / or etching. This allows the deformation resistance to be influenced or adjusted, in particular reduced.

[0116] Thus, the difference in the size of the surface areas of the two segments of the frame-shaped deformation region and / or the two deformation regions and / or the two deformation sub-regions can be achieved by saw cuts of different depths into the deformation element.

[0117] According to a further embodiment, the structuring of the functional element and the structuring of the deformation element, in particular to enlarge the surface of the deformation region, takes place in the same process step, in particular a sawing step. This allows for the elimination of process steps and simplifies the method.

[0118] In a further embodiment of the invention, the surface areas of the respective regions of the first and / or second contact surface, which delimit or adjoin the two segments of the frame-shaped deformation region and / or the two deformation regions or the two partial deformation regions, are of different sizes, whereby locally different deformation resistances can be caused in order to achieve or promote a tilting of the functional element.

[0119] In a further embodiment, the outer edge of the first and / or second frame-shaped contact surface, in particular of the frame-shaped overlapping region of the first and / or second contact surface, describes a first geometric figure and the inner edge describes a second geometric figure, wherein the first and the second geometric figure are each independently selected from the group consisting of rectangle, trapezoid, in particular isosceles or right-angled trapezoid, circle and triangle.

[0120] By combining appropriate geometries for the outer and inner edges, differently shaped contact surfaces or overlapping areas of the contact surfaces and thus differently designed deformation areas can be created, whereby locally different deformation resistances can be set.

[0121] Thus, in one exemplary embodiment, the outer and inner edges of the frame-shaped overlapping region of the first and / or second contact surface are each described by a rectangle whose circumcenters do not coincide, wherein, in particular, an axis of symmetry of the rectangle describing the inner edge and an axis of symmetry of the rectangle describing the outer edge lie on the same straight line. As a result, two opposite legs of the respective frame-shaped overlapping region have identical surface areas, while the other two opposite legs have different surface areas, allowing the deformation region or its deformation resistance to be adjusted asymmetrically.

[0122] In a further embodiment, a region of the deformation element is provided with a stabilizing layer that counteracts the deformation of the deformation element or the deformation region, in particular locally. In particular, the stabilizing layer borders the deformation region or covers at least part of the surface of the deformation region. Preferably, the stabilizing layer can border one of the two segments of the frame-shaped deformation region and / or one of the two deformation regions or deformation subregions and / or cover at least part of the surface of one of the two segments of the frame-shaped deformation region and / or one of the two deformation regions or deformation subregions.

[0123] This allows areas of the deformation element or deformation zone to be reinforced or stabilized to counteract deformation in these areas. In conjunction with areas of the deformation element that are not provided with a stabilizing layer, this can promote or support the tilting of the functional element.

[0124] When shaping the deformation element or when deforming the deformation area during the heating and deformation process step, the flow properties of the deformation area or of the material of the deformation area, as they are present in particular near and above the softening point or the solidus temperature, are utilized.The advantage of this type of shaping, in particular also referred to as glass flow, compared to other shaping or embossing processes, such as glass deep drawing or glass embossing (for example, blank pressing), is primarily that it enables the production of optical components with substrate or wafer dimensions, in particular substrate or wafer diameters greater than or equal to 80 mm, preferably greater than or equal to 150 mm, particularly preferably greater than or equal to 300 mm, with high surface quality, in particular low surface roughness, high surface flatness and high plane parallelism of the surfaces of the substrate sides.

[0125] Particularly when the starting substrate is made of glass, the surface roughness of optical components produced, for example, by glass deep drawing or glass stamping is often unsatisfactory. Substrates formed by glass drawing are roughened and cannot meet the requirements of, for example, an optical window.

[0126] With molding, the maximum dimensions of the optical components that can be produced are severely limited. Furthermore, this stamping process requires very high-quality, durable, and therefore expensive stamping tools, which limits flexible production.

[0127] During the heating and deforming process step, at least a part of the deformation region is heated and deformed in such a way that the functional element is deflected at least partially or in regions, in particular shifts, inclines and / or twists (torsion).

[0128] If the deformation element or the deformation area is heated, particularly in the area of the first and / or second contact surface, a high-quality surface area of the functional element and / or the carrier, with, for example, low roughness and flatness deviation, can be molded onto the surface of the deformation element through contact with the deformation element. This has the advantage that the surface quality requirements of the provided deformation element can be lower in the corresponding area, and a potentially necessary processing step, such as polishing, can be omitted.

[0129] In order to enable such a molding or in particular to maintain the shape of the functional element and its surface properties, in particular the upper cooling temperature or the solidus temperature of the material of the functional element and / or the carrier is greater than the upper cooling temperature or the solidus temperature of the material of the deformation element or the deformation region, wherein the temperature difference between the respective upper cooling temperature or solidus temperature of the material of the functional element and / or the carrier and the material of the deformation element or the deformation region should be as large as possible, in particular greater than or equal to 100K.For example, if the functional element and / or the carrier consists of silicon and the deformation area of borosilicate glass, the solidus temperature or melting temperature of silicon and the upper cooling temperature of borosilicate glass are decisive for the difference formation.

[0130] In an advantageous embodiment, the softening temperature or liquidus temperature of the material of the deformation element or the deformation region is below the softening temperature or liquidus temperature, in particular below the upper cooling temperature or solidus temperature, of the material of the functional element and / or the carrier. This allows for an efficient deformation process while simultaneously maintaining the shape of the functional element and / or the carrier.

[0131] Accordingly, in the heating and deforming process step, at least a part of the deformation region, in particular the entire deformation region or the deformation element, is preferably brought to a temperature which is above the upper cooling temperature or solidus temperature of the material of the deformation region or the deformation element and below the upper cooling temperature or solidus temperature of the material of the functional element and / or the carrier.

[0132] The temperature interval between the solidus and liquidus temperatures of a material or substance is called the melting interval or melting range. For example, in eutectic alloys and pure metals, the solidus and liquidus temperatures coincide. In these cases, the solidus and liquidus temperatures have the same value, which is called the melting point.

[0133] In particular, at least a part of the deformation region, in particular the entire deformation region or the deformation element, is brought to a temperature during the heating and deformation process step which lies between the softening temperature minus 150°C and the softening temperature plus 100°C of the material of the deformation region or the deformation element.

[0134] Particularly with regard to the use of glasses or glass-like materials for the deformation area or the deformation element, the upper cooling temperature and the softening temperature are important properties for assessing the suitability for the deformation process.

[0135] Below the upper cooling temperature, the viscosity of a glass, for example, and thus its resistance to deformation, is usually too high for a practical forming process. Above the upper cooling temperature, the viscosity decreases and the forming properties improve. In the softening temperature range, the corresponding material exhibits particularly favorable forming properties, especially with regard to viscosity.

[0136] When using borosilicate glass, with a softening temperature of about 820 °C, temperatures between about 700 °C and about 900 °C are appropriate for the heating and forming process step.

[0137] For each glass, a cooling range can be defined, which is limited by the upper and lower cooling temperatures. These temperatures are defined by the viscosity, with the upper cooling temperature being the temperature at which the glass has a viscosity of 10 13 < or 10 13.3 < dPa s. At the lower cooling temperature, the viscosity is 10 14.5 < dPa s.

[0138] The method for determining the upper cooling temperature is a direct viscosity determination, which, as a thread-pulling method, is related to the Littleton method described below, except that the temperature is sought at which, under a load of 1000 g, the thread elongates at a rate of 0.136 mm / min. The viscosity is then 10 13< or 10 13.3< dPa s. If the furnace is cooled further, the value for the lower cooling temperature is obtained by extrapolation to the extension rate of 0.0043 mm / min.

[0139] The softening temperature or softening point, also called the Littleton temperature or Littleton point, is determined using a method developed by Littleton. A thread of material (for example, a glass thread) with a diameter of 0.65 mm to 1.0 mm and a length of 22.9 cm is suspended in a furnace of a specific design. At a heating rate of 5 to 10 K / min, the lower end of the thread is observed hanging out of the furnace. As the temperature increases, the thread elongates under its own weight. The temperature at which the elongation is 1 mm / min is called the Littleton temperature. Most glasses or glass-like materials have a viscosity of approximately 10 7.6 < dPa s at this temperature (Scholze, Horst, "Glas - Nature, Structure and Properties," 3rd edition, Springer Verlag, p. 151).

[0140] Preferably, at least part of the overlapping region of the first contact surface and at least part of the overlapping region of the second contact surface are retained or maintained during heating and deformation, wherein the overlapping region of the first contact surface and the overlapping region of the second contact surface in particular delimit the same deformation region. Accordingly, the contact between the deformation element and the carrier in the overlap region and the contact between the functional element and the deformation element in the overlap region are at least partially not released during heating and deformation in order to ensure effective force transmission to the deformation region during heating and deformation and / or to mold one or more surface regions of the functional element and / or the carrier onto the deformation element.

[0141] Particularly preferably, the overlapping areas remain completely or completely preserved or remain intact during heating and deformation.

[0142] The heating and deformation process step is preferably carried out in a time-controlled manner or until the deformation element and / or the functional element come into contact with a deflection limiter, which, for example, limits the maximum desired deflection due to deformation. A tool, a functional element, and / or the carrier, in particular the bottom surface of the recess in the carrier, can serve as a deflection limiter. This can increase the accuracy of the deflection or improve the reproducibility of the optical component.

[0143] During the heating and deformation process step, at least a portion of the deformation region is deformed by a force (deformation force), whereby the deformation can extend beyond the deformation region to regions of the deformation element that are not part of the deformation region. In particular, regions adjacent to the deformation region can also be deformed by the deformation process due to the material coupling to the deformation region, since the stress or velocity profiles in the deformation element caused by the deformation force can extend beyond the deformation region.

[0144] The deformation of the deformation region can preferably be caused by the dead weight of the functional element and / or the deformation region or the deformation element and / or by an externally applied force.

[0145] An externally applied force or deformation force can expediently be based on a mechanical, for example a pneumatic, and / or magnetic and / or electrical and / or piezoelectric interaction.

[0146] In a further embodiment, as previously described, the externally applied force is effected by a pressure difference between two, in particular opposite, sides of the functional element and / or by a pressure difference between two, in particular opposite, sides of the deformation element. As with deformation by dead weight, this method of force application also does not require the deformation element and / or the functional element to be brought into contact with another object, such as a stamping tool, which could reduce the surface quality of the deformation element and / or the functional element. Accordingly, this type of force application can preserve or ensure a high surface quality of the deformation element and / or the functional element.

[0147] In addition, in this case, the heating and deformation can be carried out until a change in the volume of the cavity caused by the deformation of the deformation area or the deformation element leads to a pressure in the cavity that corresponds to the ambient pressure.

[0148] Specially designed forming devices are also suitable for applying a deformation force, whereby the functional element can assume a protective function to prevent contact between the forming device and the deformation element, particularly during the heating and deformation process step. Contact between the forming device and the deformation element could lead to adhesion, which could cause defects in the deformation element when the forming device is removed.

[0149] In addition, the functional element can distribute a force applied locally by the forming device into a surface force effect on the deformation area.

[0150] In addition to the point of application of the deformation force, properties such as the deformation resistance of the deformation area or the deformation element in relation to the applied deformation force are decisive for how the functional element is deflected.

[0151] As already described, the functional element can be connected to the deformation element during its application. Additionally, or alternatively, it is possible for the functional element to be arranged on the deformation element during its application, and for the connection between the functional element and the deformation element to be established during the heating and deformation process step, in particular by thermal bonding.

[0152] In particular, if the connection between the functional element and the deformation element is created during heating and deformation, an additional process step for the connection can be eliminated, which could represent an additional thermal load, particularly for the functional element, and could adversely affect the quality, especially the optical quality. Furthermore, thermal bonding can ensure particularly effective molding of the surface area or surface structure of the functional element onto the deformation element.

[0153] A connection between the functional element and the deformation element can ensure high positional stability of the elements, especially their contact surfaces, relative to each other, thus preserving and / or protecting and / or generating a high surface quality of the contact surface(s). Furthermore, the connection can ensure effective force transmission for deformation of the deformation area or the deformation element.

[0154] By connecting, in particular by means of a material bond, the functional element to the deformation element, a stable position of the elements relative to one another can be ensured even after heating and deformation. This allows, while maintaining the connection, an optical component to be produced that can comprise both elements and thus, for example, different materials, or so that the connected elements can be subjected to a separation step independent of the shaping device or the devices for applying the deformation force, for example, a selective etching step. Such a separation of the shaping and separation steps also allows deformation elements with complex structures—which in particular exhibit large topographical contrasts, such as narrow, deep trench structures or surfaces formed at right angles to one another—to be separated from the functional element without any loss of quality.

[0155] In particular, if the at least one functional element does not have to fulfil any further functions, it is preferably removed at least partially, preferably completely, or separated from the deformation element in a further method step.

[0156] Particularly preferably, the removal is carried out in such a way that the functional element can be reused and used multiple times, thereby increasing the efficiency of the process and reducing the manufacturing effort or costs.

[0157] This can be achieved, for example, by providing the functional element with a sacrificial layer, at least in the region that is connected to the deformation element, which is removed after the deformation of the deformation element to release the functional element. Alternatively, the sacrificial layer can first be applied and structured on the deformation element, with the functional element then being arranged on the sacrificial layer and thus on the deformation element or connected to the sacrificial layer in a subsequent process step. A preferred sacrificial layer contains or consists of silicon, germanium, zinc oxide, molybdenum, and / or tungsten.For such a functional element, which is connected to the deformation element via a sacrificial layer, materials such as high-melting or high-temperature-resistant glasses (for example Corning Eagle XG ®< , Corning Lotus Glass ®< , Schott AF32 ®< ) can be used, which, when directly connected to the deformation element, can only be removed with great effort, provided that the deformation element or the finished component is not damaged.

[0158] For certain applications, it may be advantageous for one or more parts of the functional element to remain on the deformation element or the finished optical component, for example as a frame-shaped stabilizing structure or aperture structure.

[0159] The carrier is also preferably removed completely after forming. In some cases, however, the microsystems to be encapsulated are arranged on the carrier, so it may be advisable to retain the connection between the forming element and the carrier.

[0160] In an advantageous embodiment, at least one region of the deformation element and / or the functional element is provided with at least one finishing coating - in particular with an anti-reflective coating, an antistatic coating, a reflection coating and / or an absorption coating, and / or functional surface structures, whereby the functionality of the optical component can be improved.

[0161] Preferred finishing coatings are anti-reflective coatings, which, for example, further reduce reflections on a cover, especially on its optical windows, and thus radiation losses. Such anti-reflective coatings can be realized, for example, using layer systems of magnesium fluoride and titanium oxide, or silicon dioxide and titanium oxide.

[0162] Furthermore, antistatic coatings can be used to minimize electrical charging of the optical component.

[0163] A material suitable for antistatic coatings in optical applications is ITO (indium tin oxide) because it has a high electrical conductivity when doped and a high transparency over a wide wavelength range.

[0164] Furthermore, it can be advantageous to apply reflective coatings, such as metal layers, as finishing coatings. After structuring, these can form locally reflective areas, for example, to spatially limit an incoming light beam (aperture function) or to form a static deflection mirror adjacent to the optical windows.

[0165] Other preferred finishing coatings are absorption coatings that absorb electromagnetic radiation of specific wavelengths or entire wavelength ranges.

[0166] For the purposes of the invention, functional surface structures are geometric modifications of the surface in the micrometer and / or nanometer range, through which certain surface properties can be specifically influenced. For example, the preferred use of moth-eye structures (see publication DG Stavenga, S. Foletti, G. Palasantzas, K. Arikawa "Light on the moth-eye corneal nipple array of butterflies", Proceedings of the Royal Society B (2006) 273, 661-667, doi: 10.1098 / rspb.2005.3369, Published online 6 December 2005), whose structural dimensions are below the wavelength of the radiation used in the application, can reduce the refractive index of a boundary layer—such as that between a glass surface and the surrounding air—which is why moth-eye structures are suitable for anti-reflective coating of surfaces. Such an anti-reflective coating is particularly advantageous when a coating proves to be unsuitable for adhesion reasons.

[0167] Moth-eye structures can be created on the surfaces of the deformation element, for example, using embossing processes after the deformation element has been formed. However, embossing such structures into inclined and / or displaced surfaces is extremely problematic. Moth-eye structures can be created, particularly on inclined surfaces, by exploiting the flow properties of the deformation element.

[0168] Accordingly, in a preferred embodiment, moth-eye structures are produced as functional surface structures in such a way that, before the functional element is arranged and / or brought into contact with the deformation element, at least the region of the functional element that is brought into contact with the deformation element is provided with a negative mold of the moth-eye structures, and after the functional element is arranged and / or brought into contact with the deformation element, during the shaping of the deformation element, the moth-eye structures are produced on the contact surface of the deformation element by molding the negative mold in the functional element onto the contact surface of the deformation element, in particular onto the transmission surfaces (for example of a prism).The material of the deformation element flows into the hollow shapes defined by the negative mold in the functional element, creating the corresponding surface geometry. The shaping of the deformation element and the creation of the moth-eye structures can also be carried out separately or sequentially in independent steps.

[0169] In a further preferred embodiment, the finishing coating is produced in such a way that, before arranging and / or bringing the functional element into contact on / with the deformation element, at least the area of the functional element that is brought into contact with the deformation element is provided with the finishing coating and then a connection between the deformation element and the functional element is established by a connection between the finishing coating and the deformation element, or that, before arranging and / or bringing the functional element into contact on / with the deformation element, the finishing coating is applied to the deformation element and then the functional element is arranged on the finishing coating and / or brought into contact with it,wherein, after the deformation step, the functional element is at least partially removed, and the finishing coating remains on the deformation element. Applying the finishing coating to the deformation element before deformation of the deformation element allows for a homogeneous finishing coating with small tolerances in the thickness of the individual layers of the finishing coating, particularly on inclined optical areas, such as the transmission surface of a prism. When applying the finishing coating after deformation of the deformation element, the deposition and any structuring of the individual layers must be carried out, for example, on inclined areas or surfaces.which, particularly when using anisotropic deposition processes, can result in differences in the thickness of the individual layers and thus location-dependent differences in the properties or in the optical functionality of the finishing coating and thus of the optical component.

[0170] A broadband anti-reflective coating produced according to this embodiment could, for example, be based on a layer sequence of silicon oxide and silicon nitride. In this case, the silicon oxide layer is first applied to the functional element, for example, made of silicon. The silicon nitride layer is then applied to the silicon oxide layer. The layer sequence of functional element, silicon oxide layer, and silicon nitride layer is then bonded to the deformation element by bonding the silicon nitride layer to the deformation element. After selective removal of the functional element, a layer sequence of deformation element, silicon nitride layer, and silicon oxide layer remains, thus forming a deformation element provided with an anti-reflective coating. Titanium dioxide can also be used as an alternative to silicon nitride.

[0171] Combinations of finishing coatings and functional surface structures, for example a combination of antistatic coating and moth-eye structures, can also improve the functionality of the optical component. Beispiele

[0172] Without limiting its generality, the invention is described in more detail below using examples.

[0173] Fig. 2-2d show a cover array 22 produced by the method according to the invention with inclined optical windows 3 and the use for encapsulating micromirrors 25.

[0174] Fig. 3a-3h show the sequence of steps of an embodiment for structuring a glass wafer 1 to produce openings 8a by means of glass flow.

[0175] Fig. 4a-4i , Fig. 4k und Fig. 4m show the sequence of steps of an embodiment for producing a cover array 22 with inclined or inclined and shifted optical windows 3 according to the method according to the invention for differently designed deformation areas and using different pressures.

[0176] Fig. 5a-5g show the sequence of steps of a further embodiment for producing a cover array 22 with inclined optical windows 3 according to the method according to the invention using a tool or support 5 with ventilation channels 23 acting as a carrier 5.

[0177] Fig. 6a-6f and Fig. 7a-7e show the sequence of steps of further embodiments for producing a cover array 22 with inclined optical windows 3 according to the method according to the invention using a shaping device 30 for applying force.

[0178] Fig. 8a-e show the sequence of steps of an embodiment for producing a cover array 22 with inclined optical windows 3 according to the method according to the invention using a carrier 5 with support structures 21.

[0179] Fig. 9a-9e show the sequence of steps of a further embodiment for producing a cover array 22 with inclined optical windows 3 according to the method according to the invention using a stabilization layer 20.

[0180] Fig. 10a-10i , Fig. 11a-11f , Fig. 12a-12b and Fig. 13a-13f show the sequence of steps of further embodiments for producing a cover array 22 with inclined or inclined and shifted optical windows 3 according to the method according to the invention using one or more cavities 12, 13, in particular between the carrier 5 and the deformation element 1.

[0181] Fig. 14a-14d show the sequence of steps of a further embodiment for producing a cover array 22 with inclined and shifted optical windows 3 according to the method according to the invention using recesses 10 in the carrier.

[0182] Fig. 15a-15d show the sequence of steps of a further embodiment for producing a cover array 22 with inclined and shifted optical windows 3 according to the method according to the invention using cavities 11 between the deformation element 1 and the functional elements 2.

[0183] Fig. 16a-16f show the sequence of steps of an embodiment for producing an array of prisms or inclined mirrors 22b according to the method according to the invention using a deformation element 1 that is planar on both sides.

[0184] Fig. 17a-17g show the sequence of steps of an embodiment for producing an array of prisms or inclined mirrors 22b according to the method according to the invention using island-shaped deformation elements 1.

[0185] Fig. 18a-18b und Fig. 19a-19b show the sequence of steps of further embodiments for producing a cover array 22 with shifted optical windows 3 according to the method according to the invention.

[0186] Fig. 2 shows a lid array 22 with inclined optical windows 3 produced by the method according to the invention, wherein a suitable lid array 22 can be used to encapsulate an entire silicon wafer 24.

[0187] The inclined optical windows 3 are arranged in a two-dimensional array and typically have an inclination of between approximately 5° and approximately 20°, preferably approximately 15°, relative to the contacting surface 22a of the cover array 22 surrounding each window 3. The contacting surface 22a surrounding each inclined optical window 3 is closed in a frame-like manner and is flat. Correspondingly dimensioned, frame-like, closed, flat surfaces are provided on the carrier substrate or silicon wafer 24 as counter-contacting surfaces, such as Fig. 2a This enables a hermetically sealed connection to the environment.

[0188] The inclined optical windows 3 are provided on both sides with an anti-reflective coating consisting of a layer system of silicon dioxide and titanium oxide.

[0189] After bonding the cover array 22 to the silicon wafer 24, the contact pads 27 arranged on the silicon wafer 24 are exposed and the chips are separated, resulting in a micromirror 25 encapsulated with a cover 22. Fig. 2a-2d .

[0190] Fig. 4a-4m show the sequence of steps of several embodiments for producing a cover array or cover 22 with inclined or inclined and shifted optical windows 3 according to the method according to the invention. The deformation element 1 provided at the start of the process is a glass wafer made of borosilicate glass, which is flat on both sides and has plane-parallel substrate planes 1a, 1b and has a thickness between approximately 500 µm and approximately 1000 µm, in this case 725 µm. Both wafer sides or wafer planes 1a, 1b of the glass wafer 1 are polished and thus have a high surface quality with a square surface roughness of approximately 1 to 3 nm. In addition, the glass wafer 1 has rectangular ( Fig. 4f ) or trapezoidal ( Fig. 4g ) openings 8a, which are realized by a sandblasting or milling process.

[0191] One side 1b of the glass wafer 1 is connected to a silicon wafer 5, which acts as a carrier 5, by anodic bonding, whereby the process results in a hermetically sealed connection ( Fig. 4b ). The other side 1a of the glass wafer 1 is hermetically sealed by fusion bonding or thermal bonding with another 850 µm thick glass wafer 4 made of high-temperature resistant or higher-melting glass or silicate glass (e.g. Corning Eagle XG ®< , Corning Lotus Glass ®< , Schott AF32 ®< , Hoya SD2 ®< ), which acts as functional layer 4 ( Fig. 4c ). Alternatively, the connection step can be carried out by anodic bonding, for which purpose the further glass wafer 4 is coated with a conductive layer, such as polysilicon, in a previous step.

[0192] The two glass wafers 1, 4 are joined at temperatures of approximately 400°C and a pressure of approximately 10 to 20 mbar or approximately 800 to 1000 mbar.

[0193] The further glass wafer 4 has flat, plane-parallel substrate planes on both sides, wherein the two wafer sides or wafer planes are polished and have a square surface roughness of approximately 1 to 3 nm.

[0194] By connecting the glass wafer 1 with the silicon wafer 5 and the further glass wafer 4, hermetically sealed cavities 12 ( Fig. 4c ).

[0195] An alternative possibility for producing a glass wafer 1 with openings 8a is described in the Fig. 3a-3h In a first step, temporary recesses 9 are created in the glass wafer 1 by etching, sandblasting, drilling, milling and / or laser beam processing ( Fig. 3a ). By connecting the glass wafer 1 with another glass wafer 4 ( Fig. 3b ), which in the further process can form the basis for the functional elements 2 and accordingly function as a functional substrate or functional layer 4, by means of fusion bonding or with a silicon wafer 5 ( Fig. 3c ), which can function as a carrier 5 in the further process, the temporary recesses 9 in the glass wafer 1 are hermetically sealed by means of anodic bonding. Alternatively, instead of the temporary recesses 9 in the glass wafer 1, temporary recesses 9 can also be formed in the silicon wafer 5 or in the further glass wafer 4 in order to generate hermetically sealed cavities 14 between the glass wafer 1 and the silicon wafer 5 or the further glass wafer 4.

[0196] During the bonding step, a pressure of approximately 800 to 1000 mbar is generated in the cavities 14. By heating the borosilicate glass wafer 1 to 700°C, which is within the softening temperature range of borosilicate glass, the glass wafer 1 becomes soft or flowable. Furthermore, the pressure in the cavities 14 increases to approximately 1200 to 1600 mbar. Since the heating takes place at atmospheric pressure, the excess pressure in the cavities 14 causes a deformation of the glass wafer 1 ( Fig. 3d, Fig. 3e ). The cavities 14 are opened by grinding and polishing ( Fig. 3f, Fig. 3g ) and the openings 8a in the glass wafer 1. The ground side of the glass wafer 1 can then be connected to a carrier 5 or a functional substrate 4 in order to close the openings 8a and create hermetically sealed cavities 12 ( Fig. 3h ).

[0197] The structuring of the further glass wafer 4 to produce several functional elements 2, which can function, for example, as optical windows 3, as well as to realize a desired deformation area 15 ( Fig. 4d - finely dotted area of the glass wafer 1) is carried out by means of a sawing step in which the hermetically sealed cavities 12 are retained ( Fig. 4d ). The further glass wafer 4 is sawn in such a way that each functional element 2 produced closes one of the cavities 12 ( Fig. 4f und 4g ). Alternatively, the functional elements 2 can be produced in such a way that each functional element 2 closes the cavities 12, which according to Fig. 4f or Fig. 4g arranged in a column or vertically.

[0198] In addition, the same sawing step results in a structuring of the glass wafer 1, in which depressions 8b are created, thereby shaping the deformation region 15, in particular in a frame shape, and influencing the deformation resistance. In particular, the deformation region 15 is thereby provided with additional surface regions 17 in order to reduce the local deformation resistance of these regions of the deformation region 15 ( Fig. 4e ) and to optimise the process in terms of material and time expenditure.

[0199] In addition or alternatively, a resistance asymmetry of the deformation area 15 according to Fig. 4d can be achieved by varying the width of the frame-shaped deformation area 15. The top views of the Fig. 4f und 4g show the differently designed second contact surfaces 7 between the glass wafer 1 and the functional elements 2 after the sawing step, wherein the design of the second contact surfaces 7 is decisive for the shape of the deformation region 15.

[0200] To ensure the desired resistance asymmetry, the outer edge 18 and the inner edge 19 of one of the frame-shaped second contact surfaces 7 are each described by a rectangle whose circumcenters do not coincide, wherein an axis of symmetry of the rectangle describing the inner edge 19 and an axis of symmetry of the rectangle describing the outer edge 18 lie on the same straight line. As a result, two opposite sides of the frame-shaped second contact surface 7 are equal, and the other two sides are designed with different widths ( Fig. 4f ).

[0201] In the embodiment according to Fig. 4g The outer edge 18 of one of the frame-shaped second contact surfaces 7 is described by a rectangle, whereas the inner edge 19 is described by an isosceles trapezoid. As a result, two opposite sides of the frame-shaped second contact surface 7 are tapered, while the other two sides are not. This also achieves a resistance asymmetry of the deformation region 15, taking into account a corresponding support 5 or a correspondingly designed first contact surface 6.

[0202] In the next process step, the layer system comprising glass wafer 1, functional elements 2, and silicon wafer 5 is heated. When using a glass wafer 1 made of borosilicate glass, with a softening temperature of approximately 820°C, the layer system is heated to approximately 700°C, whereby the glass wafer 1 softens and begins to flow. Since the softening temperature of the functional elements 2, which are made of a silicate glass (for example, Corning Eagle XG ®< ), is 971°C and thus significantly higher than the softening temperature of the glass wafer 1, the shape of the functional elements 2 is retained, which also ensures optimal transfer of the deformation force to the glass wafer 1.

[0203] Due to the increased temperature compared to the bonding process, the pressure in the cavities 12 increases from approximately 10 to 20 mbar to approximately 20 to 30 mbar or from approximately 800 to 1000 mbar to approximately 1200 to 1600 mbar. The corresponding negative or positive pressure relative to the ambient atmospheric pressure leads to a force acting on the glass wafer 1, in particular the deformation region 15, which causes a deformation of the glass wafer 1 or the deformation regions 15.

[0204] Due to the resistance asymmetry of the respective deformation area 15, a tilting ( Fig. 4i - Overpressure in cavity 12, Fig. 4k - negative pressure in the cavity 12 ) or to a tilting and shifting ( Fig. 4h und Fig. 4m - Overpressure in the cavity 12) of the functional element 2 delimiting the respective cavity 12. The deformation step is initiated upon contact of the respective functional element 2 with a deflection limitation, for example a neighboring functional element ( Fig. 4m ), or after the pressure in the cavities 12 has reached the value of the ambient pressure due to deformation.

[0205] In a further step, the silicon wafer 5 is selectively removed from the glass wafer 1 by wet-chemical etching in potassium hydroxide and the cover array 22 is separated from the formed glass wafer 1 and functional elements 2, wherein the separation process can alternatively also be carried out after the encapsulation process, as in Fig. 2a-2d has already been described.

[0206] In a further embodiment according to Fig. 5a-5g Instead of a silicon wafer, a tool or a support with ventilation channels 23 is used as the carrier 5. After the glass wafer 1 made of borosilicate glass has been connected to the other glass wafer 4 ( Fig. 5b ) and the structuring of both glass wafers 1, 4 by a sawing step to produce functional elements 2 and to design the deformation areas 15 ( Fig. 5c ) the structured glass wafer composite comprising glass wafer 1 and the functional elements 2 is brought into contact with the support 5, which acts as a carrier 5, in an adjusted manner, wherein the support 5 consists of graphite or wherein at least the surface areas of the support 5, which are brought into contact with the structured glass wafer composite 1, 2, are coated with graphite ( Fig. 5d ). The venting channels 23 of the support 5 are adapted to the structure of the structured glass wafer composite 1, 2, so that each of the cavities 12 closed by the structured glass wafer composite 1, 2 and the support 5 is connected to at least one venting channel 23 ( Fig. 5e ). During the subsequent heating and deformation, a pressure below the ambient pressure (e.g., atmospheric air pressure) is generated in the cavities 12 via the venting channels 23 by means of a vacuum pump. The resulting force acting on the functional elements 2 or on the deformation regions 15, and the configuration of the deformation regions 15, generates a resulting torque acting on each functional element 2, which, in conjunction with the flowable borosilicate glass of the glass wafer 1 caused by the heating, leads to the inclination or tilting of the functional elements 2 in the direction of the support 5 ( Fig. 5f ). After the desired inclination has been achieved, ambient pressure is set in the cavities 12 via the vent channels 23 so that the formed glass wafer composite 1, 2 can be removed from the support 5 ( Fig. 5g ). Edition 5 can be reused for another process run.

[0207] In addition to ensuring a pressure difference to generate a force effect, the deformation force can also be introduced via a shaping device 30, as the Fig. 6a-6f and Fig. 7a-7e show.

[0208] The Fig. 6a-6c show a variant using a silicon wafer as carrier 5 and the Fig. 6d-6f show a variant using a support as a carrier 5. Both the shaping device 30 and the support 5 consist of a material or are coated with a material that adheres as little as possible to the structured or shaped glass wafer composite 1, 2 during heating and deformation, such as graphite. By appropriately adjusting the shaping device 30, the deformation force can be specifically introduced in such a way that a tilting of the functional elements 2 or the optical windows 3 is ensured. By means of resistance-asymmetric deformation regions 15 ( Fig. 6a-6c ) can additionally support tilting. Furthermore, the shaping device 30 can be designed such that it simultaneously functions as a stop to precisely realize a predetermined angle of inclination of the optical window 3. Alternatively, the deformation force is maintained until the desired inclination of the functional element 2 is achieved. After heating and deformation, the shaping device 30 is removed from the shaped glass wafer composite 1, 2, so that the shaped glass wafer composite 1, 2 is released from the support 5 ( Fig. 6f ) or the silicon wafer 5 can be removed.

[0209] In Fig. 7a-7e The use of a shaping device 30 with a wedge-shaped stamping element 31 is shown. In particular, the surface of the stamping element 31 is made of graphite or is coated with graphite, and its shape enables self-adjusting placement of the shaping device 30 on the structured glass wafer composite 1, 2. The shaping device 30 can also function as a stop, allowing a precise angle of inclination of the functional elements 2 to be set.

[0210] In a further embodiment, the stamping element 31 has an inclined stamping surface which has the desired inclination for the optical windows 3.

[0211] According to the embodiment according to the Fig. 8a-8e the structured glass wafer composite 1, 2 ( Fig. 8a ) made of the borosilicate glass wafer 1 and the functional elements 2 (for example optical windows 3) are brought into contact with a support 5 in an adjusted manner ( Fig. 8b-8c ), which, in addition to venting channels 23, has support structures 21. After contact has been established, a pressure below the ambient pressure is set in the cavities 12 via the venting channels 23 by means of a vacuum pump. By heating the glass wafer 1 to near its softening temperature, it is brought into a flowable state, so that the deformation region 15 is deformed by the force acting on the structured glass wafer composite 1, 2 caused by the pressure difference. By targeted local support of the structured glass wafer composite 1, 2 by means of the support structures 21, resulting torques on the functional elements 2 can be ensured and an inclination of the functional elements 2 relative to the support 5 or to the initial position of the functional elements 2 can be achieved.

[0212] The Fig. 9a-9e show an embodiment for producing a cover array 22 with inclined optical windows 3, in which the inclination of the functional elements 2 is supported by the use of a stabilization layer 20. The glass wafer composite 1, 4 comprising glass wafer 1 and further glass wafer 4 is structured after being bonded to a silicon wafer as carrier 5 in such a way that, in a first sawing step, the regions of the further glass wafer 4 are structured which are to be deflected as little as possible during the heating and deformation step ( Fig. 9a ). The saw cut is made so deep that the resulting depression 8c is partially delimited by the glass wafer 1. The thus structured further glass wafer 4 and the depression 8c are then coated with a stabilizing layer 20 made of silicon. The deposition of the approximately 1 to 5 µm thick silicon layer 20 can be carried out using PVD or CVD processes. Alternatively, the saw cut can be made so deep that part of the further glass wafer 4 remains as a stabilizing layer. The stabilizing layer 20 additionally counteracts the deformation force through its deformation and also stabilizes the area of the glass wafer 1 covered by it. Since this area of the glass wafer 1 borders the deformation area 15 and interacts with it, the stabilizing layer 20, which borders the deformation area 15 in a linear manner, additionally causes a local increase in the deformation resistance of the deformation area 15.

[0213] In a further sawing step, the final structuring of the glass wafer composite 1, 4 takes place to produce the functional elements 2 or the optical windows 3. The areas of the deformation regions 15, which are formed by this sawing step, are not stabilized by the silicon layer 20 ( Fig. 9c ), as they are designed for greater deflection. This ensures that the functional elements 2 tilt during heating and deformation ( Fig. 9d when using overpressure in the cavities 12). The silicon layer 20 also stabilizes and fixes the functional elements 2 in their position. By using a stabilizing layer 20, the areas of the deformation regions 15, which are intended for less deflection and are therefore intended to have a higher deformation resistance, can be designed to be more space-saving (e.g., narrower).

[0214] Finally, the silicon carrier 5 is removed ( Fig. 9e ) and the formed glass wafer composite 1, 2 can be separated directly or after encapsulation of a complete wafer.

[0215] In the Fig. 10a-13f the step sequences of various embodiments for producing a cover array 22 with inclined or shifted and inclined optical windows 3 are shown, in which a cavity 13 between the carrier 5 and the deformation element 1 is used to ensure the desired inclination or shift and inclination of the functional elements 2 or the optical windows 3.

[0216] One or more cavities 13 between the carrier 5 and the deformation element 1 can be formed by designing the glass wafer 1 made of borosilicate glass and / or the silicon wafer 5 with one or more recesses 8b, 10, which enclose one or more cavities 13 after contact or connection of the glass wafer 1 to the silicon wafer 5. The connection between the glass wafer 1 and the silicon wafer 5 is produced by fusion bonding, whereby the cavity 13 is hermetically sealed and a pressure can be set that can be different from both the ambient pressure and the pressure in the cavities 12. The pressure in the cavities 12 can then be adjusted when connecting the further glass wafer 4 to the glass wafer 1.

[0217] The pressure in the cavities 12 between the functional element 2, the glass wafer 1, and the silicon wafer 5 is adjusted such that during the heating and deformation process step, the pressure in the cavities 12 corresponds to the ambient pressure. As a result, there is no pressure difference between the cavities 12 and the environment that would mechanically stress the functional elements 2 or the optical windows 3. Due to the resulting reduction in mechanical stress on the functional elements 2, their original shape can be particularly well maintained even during heating and deformation. A force effect causing the deformation is achieved by the pressure difference between the cavity 13 and the environment or the cavities 12. An overpressure in the cavity 13 of approximately 100 to 200 mbar then leads to a deflection of the functional elements 2 and thus of the optical windows 3 according to Fig. 10d and Fig. 13d , a negative pressure of about 100 to 200 mbar leads to a deflection according to Fig. 10h and Fig. 13c In the case of overpressure in the cavity 13, the heating and deformation can be carried out in a vacuum furnace, with the same pressure being set in the cavities 12 as in the vacuum furnace. In the case of negative pressure in the cavity 13, the heating and deformation can be carried out at atmospheric air pressure in the furnace as well as in the cavities 12. The result after Fig. 13e is reworked by grinding and / or polishing to provide flat contact surfaces 22a for the encapsulation step ( Fig. 13f ).

[0218] In a further embodiment, during heating and deformation, there is an overpressure in the cavity 13 compared to the ambient pressure and a negative pressure in the cavities 12, resulting in a deformation according to Fig. 10i results.

[0219] The required pressure differences can alternatively be adjusted by using a corresponding support 5 with one or more vent channels 23 and compensation channels 23a, as in Fig. 11d-11f The compensating channels 23a connect the cavities 12 to the environment in order to avoid, reduce, or minimize a pressure difference. A vacuum pump is used to set a pressure in the cavity 13 via the venting channel 23 that is below the ambient pressure.

[0220] To support the shaping and accordingly in addition to the force application using a pressure difference or acting alone (without force application based on a pressure difference), a special shaping device 30 can also be used in these cases, as already described ( Fig. 11b ).

[0221] The Fig. 12a-12b also show an embodiment in which several differently designed and / or differently pressured cavities 13 are used between the glass wafer 1 and the silicon wafer 5 in order to achieve locally different deflections of the functional elements 2 and thus a tilting or a tilting and shifting of the functional elements 2 or the optical windows 3.

[0222] The Fig. 14a-14d show the sequence of steps of a further embodiment for producing a cover array 22 with inclined and shifted optical windows 3 according to the method according to the invention using depressions 10 in the carrier 5, wherein a negative pressure is set in the cavities 12 in comparison to the ambient pressure for the application of force and for the condition of deformation.

[0223] The Fig. 15a-15d show the sequence of steps of a further embodiment for producing a cover array 22 with inclined and shifted optical windows 3 according to the method according to the invention using cavities 11 between the deformation element 1 (a glass wafer made of borosilicate glass) and the functional elements 2. The basis for the cavities 11 are functional elements 2, which have depressions 10a. By means of an overpressure set in the cavities 11 compared to the ambient pressure, the functional elements 2 are pressed away from the glass wafer 1 ( Fig. 15c ). In addition to the cavities 11, cavities 13 can be provided ( Fig. 15d ), which ensures additional pressure-related force input.

[0224] Due to the different design of the deformation area or the deformation areas 15 ( Fig. 15b ) tilting of the functional elements 2 is achieved. After removing the silicon wafer 5, the cavities 11 and the cavities 13 are opened by grinding and / or polishing.

[0225] In a modified process variant, the cavities 11 ( Fig. 15b ) can be dispensed with. In this case, force can be applied, for example, through a magnetic interaction. The local differences in the deformation resistance of the deformation regions 15 to support a tilting of the functional elements 2 are ensured, among other things, by the fact that the contact between the functional elements 2 and the glass wafer 1 only leads to a connection in the regions in which the applied force is to be transferred from the functional elements 2 to the glass wafer 1 to achieve the desired deformation. In the non-connected contact regions between the glass wafer 1 and the functional elements 2, the deformation of the deformation regions 15 eliminates the contact between the functional elements 2 and the glass wafer 1, thus creating a cavity 11 between the functional elements 2 and the glass wafer 1; equivalent to the representation in Fig. 15c , but without recesses 10a in the functional elements 2.

[0226] The Fig. 16a-16f show an embodiment for structuring a glass wafer 1 made of borosilicate glass with a thickness of 725 µm, in order to produce one or more prisms or inclined mirrors. To produce a prism array, a layer sequence consisting of two 200 µm thick silicon layers 4a, 4b and a 1 µm thick silicon dioxide layer 4c sandwiched between them is applied or deposited onto one wafer side 1a of the glass wafer 1, which has flat substrate surfaces 1a, 1b on both sides. By structuring the layer sequence 4a, 4b, 4c, functional elements 2 are produced ( Fig. 16b ). By using such a layer sequence, the accuracy of the structuring for producing the functional elements 2 can be improved. Alternatively, a 400 µm thick silicon layer can be applied or deposited as a functional layer 4 and then structured. The functional elements 2 can fulfill the function of a shaping element as well as a protective and / or molding element. As a shaping element, these functional elements 2 transfer or distribute the applied force to the glass wafer 1, thereby deforming it. As a protective element, the functional elements 2 can preserve the high surface quality provided by the glass wafer 1. As a molding element, on the other hand, a high surface quality of the functional elements 2 can be molded or transferred onto the glass wafer 1.By bringing a shaping device 30 made of quartz glass into contact with the structured silicon layer 4a, the force for deforming the glass wafer 1 is introduced (. Fig. 16c ). The asymmetric structuring of the two silicon layers 4a, 4b results in an inclination of the functional elements 2 ( Fig. 16d ). In addition, the functional elements 2 can assume the functionality of a stop due to the structuring, since when the desired inclination of the functional elements 2 is reached, the shaping device 30 comes into contact with the structured silicon layer 4b and further inclination is prevented ( Fig. 16d ). After removing the shaping device 30 and the functional elements 2, the structured glass wafer 1 can be used as a prism array or separated into several prisms.

[0227] In the case of the production of a mirror array, an aluminum layer can be deposited as a reflection coating after heating and deformation on the functional elements 2 or on the structured glass wafer 1 or its inclined transmission surfaces 3a.

[0228] A further embodiment for the production of one or more prisms or inclined mirrors according to the method according to the invention is shown in the Fig. 17a-17g . After a glass wafer 1 made of borosilicate glass, which has depressions 8b which are intended to prevent contact of the saw 32 with the silicon wafer 5 during the subsequent sawing step for producing island structures 1, has been bonded to a silicon wafer 5 by means of fusion bonding, individual island structures ( Fig.17a-17b ) as deformation elements 1. Alternatively, the island structures 1 can be created before being connected to the silicon wafer 5 (for example by sawing) and arranged on the silicon wafer 5 by means of a vacuum handler. By connecting a quartz glass wafer 4 with the island structures 1 ( Fig. 17c ) and subsequent structuring of the quartz glass wafer 4 by sawing, several functional elements 2 are produced ( Fig.17d ), whereby the generation of the functional element 2 can alternatively occur before connecting them to the island structures 1. As a result, each island structure 1 is connected to a functional element 2; but several island structures 1, which are arranged, for example, in a row or column, can also be connected to a functional element 2.

[0229] The deformation force is applied by means of the forming device 30 ( Fig. 17e ), so that a tilting of the functional elements 2 is effected ( Fig. 17f ).

[0230] If the functional elements 2 have been provided with a reflective finishing coating, the resulting optical components can be used, for example, as inclined mirrors. Alternatively, prisms are available as optical components after removing the functional elements 2 and / or the silicon wafer 5.

[0231] In the Fig. 18a-18b und Fig. 19a-19b Two embodiments are shown which show the production of a cover array 22 according to the method according to the invention with shifted optical windows 3.

[0232] In both examples, the force for the deformation is again applied on the basis of a pressure difference between the pressure in the cavities 12, in the example Fig. 18a-18b an overpressure and in the example Fig. 19a-19b a negative pressure, and the ambient pressure. A resistance-symmetric design of the deformation region 15 prevents tilting of the optical windows 3 due to the deformation of the borosilicate glass wafer 1, and displacement is achieved.

[0233] According to the example Fig. 19a-19b The pressure in the cavities 12 is not adjusted during the previous joining steps, but rather through venting channels 23 and venting recesses 23b in the support 5, which improve surface venting. The desired pressure is adjusted using a vacuum pump. The desired deflection of the optical windows 3 can be adjusted through recesses 10 in the support 5, with the support 5 acting as a deflection limiter. This allows for the production of particularly precise optical components. Bezugszeichenliste

[0234] 1 Deformation element 1a, 1b Wafer sides or substrate surfaces of the deformation element 2 Functional element 3 Optical window 3a Transmission surface, for example of the optical window or the prism 4 Functional substrate or functional layer 4a, 4b Silicon layers 4c Silicon oxide layer 5 Carrier (for example silicon substrate, graphite coating) 6 First contact surface 7 Second contact surface 8a Opening in the deformation element 8b Recess in the deformation element 8c Recess for stabilization layer 9 Temporary recess 10 Recess in the carrier 10a Recess in the functional element 11 Cavity between functional element or functional substrate / layer and deformation element 12 Cavity between functional element or functional substrate / layer,Deformation element and carrier 13 Cavity between deformation element and carrier 14 Cavity on the basis of the temporary depression 15 Deformation region 16a Overlapping region of the first contact surface 16b Overlapping region of the second contact surface 17 Surface region of the deformation region 18 Outer edge of the second contact surface 19 Inner edge of the second contact surface 20 Stabilization layer 21 Support structure of the carrier 22 Cover or cover array 22a Contacting surface of the cover or cover array 22b Array of prisms or inclined mirrors 23 Ventilation channel or ventilation channel 23a Compensation channel 23b Ventilation depression 24 Carrier substrate 25 Micromirror 26 Suspension of the micromirror 27 Contact pads 28 Incident radiation 29 Deflected radiation 30 Shaping device 31 Stamp element for Example with straight, inclined, wedge or conical punch surface 32Saw 33Frame segment,

Claims

1. Method for producing optical components, comprising the following method steps: - providing a deformation element (1) which, at least in one region, contains or consists of glass and / or a glass-like material, and a carrier (5), - bringing the deformation element (1) into contact with the carrier (5), whereby at least one first contact surface (6) is formed between the deformation element (1) and the carrier (5), - applying a functional element (2) to the deformation element (1) in such a way that at least one second contact surface (7) is formed between the functional element (2) and the deformation element (1), said at least one second contact surface (7) at least partially overlapping the first contact surface (6), so that, by way of that region of the deformation element (1) which is formed between the overlapping regions (16a, 16b) of the two contact surfaces (6, 7), at least one deformation region (15) is formed, - heating and deforming at least a part of the deformation region (15) in such a way that the functional element (2) is at least regionally displaced and / or inclined in relation to the carrier (5), - connecting the functional element (2) to the deformation element (1) during the method step of applying the functional element (2) to the deformation element (1) and / or during the method step of heating and deforming the deformation region (15), characterized in that A) the deformation element (1) is a wafer, or in that the deformation element (1) is provided by separation from and / or by structuring of a wafer, and B) in that the deformation region (15) is of frame-shaped form and / or there are formed at least two deformation regions (15) which are in contact with the same functional element (2), and / or in that the overlapping region of the second contact surface (16b) corresponds approximately to the second contact surface (7).

2. Method according to Claim 1, characterized in that, at least in one region, the deformation element (1) contains or consists of a silicate glass, preferably borosilicate glass.

3. Method according to any one of the preceding claims, characterized in that the functional element (2), the deformation element (1) and / or the carrier (5) have / has a depression and / or opening (8a, 8b, 10, 10a).

4. Method according to Claim 3, characterized in that the deformation element (1) is brought into contact with the carrier (5) and / or the functional element (2) is applied to the deformation element (1) in such a way that, by way of the depression and / or opening (8a, 8b, 10, 10a), a cavity (13, 11, 12) is formed between the deformation element (1) and the carrier (5), between the deformation element (1) and the functional element (2) and / or between the functional element (2), the deformation element (1) and the carrier (5), wherein the cavity (13, 11, 12) is in particular hermetically sealed.

5. Method according to any one of the preceding claims, characterized in that the difference between the coefficient of thermal expansion of the material of the deformation element (1) and the coefficient of thermal expansion of the material of the functional element (2) is less than or equal to 5 ppm / °K, in particular less than or equal to 1 ppm / °K.

6. Method according to any one of the preceding claims, characterized in that at least one region of the surface of the functional element (2) has a root-mean-square surface roughness of less than or equal to 25 nm, preferably less than or equal to 15 nm, particularly preferably less than or equal to 5 nm, and / or a flatness deviation per measured length of less than or equal to 180 nm / mm, in particular less than or equal to 100 nm / mm.

7. Method according to any one of the preceding claims, characterized in that the overlapping regions (16a, 16b) of the first contact surface (6) and / or second contact surface (7) are of frame-shaped form, in particular are formed around the depression and / or opening (8a, 8b) in the deformation element (1), and / or the deformation region (15) is formed in a frame-shaped manner around the depression and / or opening (8a, 8b) in the deformation element (1), and / or in that the at least two deformation regions (15) are formed diametrically around the depression and / or opening (8a, 8b) in the deformation element (1).

8. Method according to any one of the preceding claims, characterized in that the deformation region (15) has a surface (17), wherein in particular the two segments (33) of the frame-shaped deformation region (15) and / or the two deformation regions (15) and / or the two deformation sub-regions have surfaces (17) with surface areas of different sizes.

9. Method according to Claim 8, characterized in that the surface (17) of the deformation region (15) is produced and / or enlarged by structuring of the deformation element (1), in particular by sawing and / or etching.

10. Method according to any one of Claims 7 to 9, characterized in that the surface areas of the respective regions of the first contact surface (6) and / or second contact surface (7) that delimit the two segments of the frame-shaped deformation region (15) and / or the two deformation regions (15) and / or the two deformation sub-regions are of different sizes.

11. Method according to any one of Claims 7 to 10, characterized in that the outer periphery (18) of the frame-shaped overlapping region (16a, 16b) of the first contact surface (6) and / or second contact surface (7) describes a first geometrical figure and the inner periphery (19) describes a second geometrical figure, wherein the first and second geometrical figures are, independently of one another, in each case selected from the group consisting of rectangle, trapezium, in particular isosceles or right trapezium, circle and triangle.

12. Method according to any one of the preceding claims, characterized in that one region of the deformation element (1) is provided with a stabilization layer (20) which counteracts the deformation of the deformation region (15).

13. Method according to any one of the preceding claims, characterized in that the upper cooling temperature or the solidus temperature of the material of the functional element (2) is greater than the upper cooling temperature or the solidus temperature of the material of the deformation region (15), wherein the temperature difference between the respective cooling temperature or solidus temperature of the material of the functional element (2) and that of the material of the deformation region (15) is in particular greater than or equal to 100K.

14. Method according to any one of the preceding claims, characterized in that at least a part of the deformation region (15), in particular the entire deformation region (15), is, during the method step of heating and deforming, brought to a temperature which is above the upper cooling temperature or solidus temperature of the material of the deformation region (15) and below the upper cooling temperature or solidus temperature of the material of the functional element (2).

15. Method according to any one of the preceding claims, characterized in that the carrier (5) has a support structure (21) which limits a region of the functional element (2) and / or a region of the deformation element (1) in terms of the ability thereof to deflect and / or deform in such a way that inclination of the functional element (2) is supported.