Method for processing a single-crystalline substrate and micromechanical structure

Abstract

A method for processing a single-crystal substrate (102), the method comprising: • Cutting (100b) the substrate (102) along a main processing side into at least two monocrystalline substrate sections (102a, 102b), wherein the substrate (102) has a desired separation layer (202) by means of which the at least two substrate sections (102a, 102b) are connected to one another and wherein the cutting (100b) takes place by breaking the cohesion of the desired separation layer (202); • Attaching (300a) at least one single-crystalline substrate section of the at least two substrate sections (102a, 102b) to an additional substrate (302) before the severing (100b); • Forming (100c) a micromechanical structure (106) comprising the at least one single-crystalline substrate section of the at least two substrate sections (102a, 102b); and • Changing a mechanical characteristic and / or electrical characteristic of the at least one monocrystalline substrate section by means of ion implantation, wherein the change takes place before the severing (100b).

Description

The invention relates to a method for processing a single-crystalline substrate and to a micromechanical structure.Generally, a microelectromechanical system (MEMS) or a micromechanical system (MMS) may be integrated into small devices or systems that combine electrical and mechanical components with each other. For example, the term "micromechanics" may be used to describe small integrated devices or systems that include one or more micromechanical elements and possibly, but not necessarily, electrical components and / or electronic components.Generally, a microelectromechanical system may be used to provide, for example, an electromechanical transducer, e.g., actuator or sensor. An MMS can have a deflectable structure, such as a membrane or a cantilever. Used as a drive, a microelectromechanical system (MEMS) can have one or more MMS, the deflectable structure of which can be electrically deflected. As a sensor (e.g., microphone), a MEMS may provide an electrical signal in response to a deflection (also referred to as stroke) of the deflectable structure of the MMS.Aspects of electronic components are described in the following publications: DE 692 31 328 T2, DE 10 2008 000 261 A1, DE 10 2007 051 823 B4, DE 198 00 189 A1, DE 10 2007 019 639 A1, DE 10 2013 211 970 A1, DE 10 2006 026 559 A1, EP 1 133 684 B1 US 2011 / 0 073 967 A1, US 2014 / 0 072 152 A1.The invention is defined by the independent claims. Embodiments are described in the respective dependent claims.A microstructure, such as a membrane in a micro transducer (for example microphone or microspeaker) or a cantilever in an atomic force microscope (AFM), can have high requirements, in particular on the bending properties and / or the deflection behavior and the dynamic behavior under resonant conditions depending on the respective application.Both the electrical and mechanical requirements on membrane-based sensors (e.g., microphones) increase with each subsequent generation and / or with the progress of time. For example, ever smaller sensors are required which tolerate higher loudnesses or the sound pressure associated therewith, have a greater robustness and provide a greater signal-to-noise ratio (SNR).Both the SNR value and the acoustic overload (also referred to as acoustic overload-AOL) are important as evaluation criterion for assessing the quality and / or marketability of a sensor. A larger SNR allows the useful signal to stand out significantly from the background noise. At the same time, the sensor should be able to clearly record a high sound pressure (sound pressure level) (e.g. in concrets) without distortions occurring in the sound (also referred to as THD or distortion factor). The electrical performance may be closely associated with the mechanical properties of the micromechanical structure.For example, high demands are placed on the mechanical robustness of a sensor for use in devices (e.g. in smartphones, smart watches, tablet PCs, notebooks, head sets or other common utility articles) which are exposed to both mechanical loads (vibrations, falls) and external environmental influences (dust, water, etc.). The higher the mass of the terminal, the higher the mechanical load (illustratively pressure surge) for the microphone in the event of a so-called fall or impact of the device. In order to increase the robustness of a membrane-based sensor, different concepts are conventionally implemented, which, however, cannot simultaneously cover all requirements because of the available material systems.In a conventional concept, the fulfillment of the requirement for robustness, which requirement is (strongly) dependent on the mass of the terminal, is controlled via the membrane thickness. The thicker the diaphragm, the more robust it is in the case of a dynamic pressure shock. However, this makes a compromise more stringent, since the mechanical properties, such as recovery behavior and sensitivity, are also changed with increasing membrane thickness. In order to meet the requirements for the restoring voltage range while maintaining sensitivity (sensitivity), a soft membrane made of polysilicon (also referred to as poly-Si) is therefore used, which is additionally made softer by implanting it more strongly. The smaller the membrane diameter, the smaller the limit for the implantation, at which degradation of the poly-Si occurs, which leads to additional stress induction, so that the membrane bulges (also referred to as compressive membrane buckling at the implantation limit). The sensor thereby becomes unusable, so that the maximum implantation of small membrane diameters (e.g., less than 800 micrometers) is defined by the implantation limit.Since the tendency toward increasingly smaller devices is constantly increasing, it is necessary, owing to the associated reduction in the housing sizes of the terminals, likewise to reduce the MEMS and thus the membrane diameter. In order to maintain the functionality of the MEMS, it is necessary to maintain a sufficient distance from the implantation limit during the implantation. This can be compensated for in a predefined recovery voltage range merely by reducing the membrane thickness, which, however, in turn results in a lower robustness.Therefore, with small diaphragm diameters, it is conventionally accepted that the sensor has a low life expectancy or a low sensitivity.In an alternative concept, geometric modifications are conventionally made to the MEMS that influence the mechanical properties. For example, so-called ventilation flaps are incorporated into the diaphragm, which mitigate a pressure surge and thus compensate for a lower robustness of the diaphragm. However, the ventilation flaps require a precise setting of the so-called corner frequency (corner frequency or cut-off frequency). Alternatively, so-called corrugation rings are incorporated into the membrane, at which the membrane is corrugated. The implementation of the corrugation rings and / or the ventilation flaps increases the costs during production, generates additional voltage points in the membrane or counter electrode and increases the risk of the membrane "sticking" (also referred to as embroidering) to other components, for example in a dual-electrode configuration (also referred to as dual-back plate arrangement).According to various embodiments, it has been recognized that the importance of stress decoupling in membrane-based sensors increases greatly, in particular since the change in the mechanical properties of conventionally used material systems has already reached its technological limit. Therefore, loads on the MEMS are likely to be reduced solely by changes in geometry and / or design. In order to open up further space for changes which are cost-effective and reliably reproducible at a low technology level, other materials are therefore required whose unmodified properties already meet or at least almost meet the requirements placed.According to various embodiments, a micromechanical structure and a method for producing the same are clearly provided, which open up further space for changes and adaptations of the mechanical properties. Illustratively, a robust membrane (e.g. for a microphone and / or pressure sensor), i.e. with a long service life, can be provided, which meets high requirements for sensitivity.Clearly, it has been recognized that a single crystal material (e.g., single crystal SiC) provides a larger space for changes and adaptations. According to various embodiments, silicon carbide (SiC) may be used as membrane material. Silicon carbide may provide a high mechanical hardness, chemical resistance (inertness) and thermal resistance, i.e. material properties which make it easier to meet at least some requirements without additional modifications, so that the space for adaptations is maintained.Conventional processes for forming SiC are limited to the use of low temperatures, e.g. less than 700° C., and / or result in polycrystalline structures. Conventional fabrication of thin deflectable membranes from a single crystalline material results in low crystalline homogeneity of the material and low homogeneity in the thickness to which the single crystalline material is thinned. This low homogeneity can result in great fluctuations in the mechanical properties, so that the requirements placed are missed. Therefore, conventionally, polycrystalline materials are used when high requirements for homogeneity are to be fulfilled.According to various embodiments, a micromechanical structure and a method for manufacturing the same may be provided for use in power electronics.According to various embodiments, a method for processing a single-crystalline substrate may include: severing the substrate along a main processing side into at least two (i.e. a plurality of, e.g. exactly two or more than two) single-crystalline substrate segments; and forming a micromechanical structure which includes at least one (i.e. exactly one or more than one) single-crystalline substrate segment of the at least two substrate segments. The substrate may optionally be attached to a support which need not necessarily be single crystalline. The at least one substrate section does not necessarily have to denote the complete part of the substrate which is separated off, but can be part of it.According to various embodiments, the severing can be effected by means of a smartcut process.According to various embodiments, the substrate and / or each substrate portion of the two substrate portions may include or be formed from a single-crystal semiconductor material, e.g. single-crystal silicon carbide (SiC), single-crystal gallium nitride (GaN) or single-crystal silicon (Si).According to various embodiments, the at least one monocrystalline substrate subsection (also referred to as first substrate subsection) may have a monocrystalline layer or be formed therefrom (or at least from a part thereof). Alternatively or additionally, the other monocrystalline substrate portion (also referred to as second substrate portion) can have a monocrystalline substrate residue or be formed therefrom (or at least from a part thereof). The other substrate section does not necessarily have to denote the complete substrate residue of the substrate which is separated off, but can be part of it.According to various embodiments, the at least one single-crystal substrate portion may have a smaller (e.g. vertical) extension than the other single-crystal substrate portion.According to various embodiments, the substrate can furthermore have a target separating layer, by means of which the two substrate segments are connected to one another; the severing being effected by holding the target separating layer together being canceled. For example, the substrate can be divided or thermally destabilized in the target separating layer. Alternatively or additionally, a mechanical force (e.g. a tensile force) can be transmitted to the target separating layer that exceeds the breaking force of the target separating layer.According to various embodiments, the method may further include: forming the target separation layer by changing a chemical composition (of the substrate) between the two substrate portions.According to various embodiments, by means of the altering, a resistance of the substrate between the two substrate segments to the severing can be reduced.According to various embodiments, the modification can be effected by means of hydrogenation.According to various embodiments, forming the target separation layer may be performed by ion implantation.According to various embodiments, by means of the ion implantation (also referred to as first ion implantation), the introduction of a first impurity into the substrate may be effected.According to various embodiments, the ion implantation may be performed through the at least one single crystal substrate portion.According to various embodiments, the method may further comprise: fastening the at least one single-crystalline substrate section to an additional substrate before the severing.The single crystal substrate section may include a suspended portion and an anchored portion (also referred to as a mounting portion) of the micromechanical structure, wherein the suspended portion is coupled (e.g., mounted) to the additional substrate via the anchored portion. For example, the anchored portion may include or be formed from at least a portion of the single crystalline substrate section and the suspended portion may include or be formed from another portion of the single crystalline substrate section. The freely suspended portion (illustratively a protrusion) may be exposed or may be exposed on mutually opposite sides and / or may protrude from the additional substrate (also referred to as protruding).According to various embodiments, the attaching may include bonding the substrate and the additional substrate to each other, e.g. by means of hydrophilic bonding, anodic bonding or thermal bonding.The first substrate section and / or the second substrate section may have a greater mechanical hardness and / or a greater modulus of elasticity than the additional substrate.According to various embodiments, fastening may be effected by means of an adhesion layer (e.g. ceramic and / or hydrophilic), which is arranged between the at least one monocrystalline substrate section and the additional substrate.According to various embodiments, the attachment may be performed by heating the adhesion layer (e.g. to a temperature in a range 110° C. of about to about 800° C. or more).According to various embodiments, the substrate may include the adhesion layer. For example, the single-crystal substrate section may be arranged between the adhesion layer and the target separation layer.According to various embodiments, the attachment may be performed by bringing the adhesion layer into physical contact with the additional substrate.According to various embodiments, the adhesion layer may be formed by chemically altering (e.g. oxidizing) the first main processing side of the substrate.According to various embodiments, the chemically altering may comprise oxidizing. For example, the adhesion layer may comprise or be formed from a native oxide layer of the substrate. In other words, the adhesion layer may include or be formed from an oxide of the semiconductor material of the substrate.According to various embodiments, the additional substrate may have an electrode (of the micromechanical structure), or the electrode (of the micromechanical structure) may be formed by means of the at least one monocrystalline substrate section. For example, the micromechanical structure formed may have the electrode. Optionally, the electrode may have a plurality of through-openings.The first substrate section and / or the second substrate section may have a greater mechanical hardness and / or a greater modulus of elasticity than the electrode, e.g. if it is provided by means of the additional substrate.According to various embodiments, forming the micromechanical structure may further include: forming the electrode over the additional substrate, wherein the electrode is arranged between the single-crystalline substrate portion and the additional substrate; or wherein the electrode includes or is formed from the single-crystalline substrate portion.According to various embodiments, forming the micromechanical structure may include forming a cavity between the electrode and the at least one monocrystalline substrate section.According to various embodiments, forming the micromechanical structure may include forming an additional electrode, wherein the at least one monocrystalline substrate portion is arranged between the additional electrode and the additional substrate; or wherein the additional electrode includes the at least one monocrystalline substrate portion or is at least formed by means thereof.The first substrate portion and / or the second substrate portion may have a greater mechanical hardness and / or a greater modulus of elasticity than the additional electrode, e.g. if it is formed over the first substrate portion.According to various embodiments, forming the electrode and / or the additional electrode may include forming a plurality of through openings in the electrode or additional electrode.According to various embodiments, forming the micromechanical structure may include forming a sensor (e.g. pressure sensor or microphone) or actuator (e.g. sound emitter) that includes the single-crystal substrate section.According to various embodiments, forming the micromechanical structure may include forming a membrane or a cantilever which(s) includes or is at least formed by the at least one monocrystalline substrate portion.According to various embodiments, forming the micromechanical structure may include exposing at least one single-crystal substrate portion on opposite sides.According to various embodiments, forming the micromechanical structure may include electrically contacting the at least one monocrystalline substrate section.According to various embodiments, the method may further include: changing a mechanical characteristic and / or electrical characteristic of the at least one monocrystalline substrate portion by means of ion implantation.According to various embodiments, by means of the ion implantation (also referred to as second ion implantation), the introduction of a second impurity into the single-crystal substrate portion may be effected. The second impurity may be different from the first impurity.According to various embodiments, the change of the mechanical characteristic and / or electrical characteristic of the at least one single-crystalline substrate section can take place before the severing or after the severing.According to various embodiments, the method may further include: forming an additional micromechanical structure including the other single-crystal substrate portion of the two substrate portions or at least a portion thereof.According to various embodiments, the at least two substrate segments may include three substrate segments (e.g. of which an additional substrate segment includes an additional single-crystal layer); wherein the micromechanical structure includes two substrate segments of the three substrate segments and / or wherein the method further includes: forming the additional micromechanical structure including another substrate segment of the three substrate segments.According to various embodiments, the substrate portion may include at least one of the following: (e.g. single crystal) silicon carbide, (e.g. single crystal) gallium nitride, a greater modulus of elasticity than one of the following: polysilicon, the substrate and / or than 200 GPa (e.g. in a range from about 200 GPa to about 600 GPa), a greater mechanical hardness than one of the following: polysilicon, the substrate and / or than 20 GPa (e.g. in a range from about 20 GPa to about 50 GPa) and / or a greater (e.g. laterally extended) single crystal region than the substrate.According to various embodiments, a micromechanical structure may include: a substrate; a functional structure arranged at the substrate; wherein the functional structure includes a functional region (also referred to as deflectable region) deflectable relative to the substrate in response to a force acting thereon; and wherein the functional region includes or is formed from a single-crystal semiconductor material, e.g. single-crystal silicon carbide (SiC), single-crystal gallium nitride (GaN) or single-crystal silicon (Si).According to various embodiments, a microelectromechanical structure may include the micromechanical structure according to various embodiments and an electrode at the substrate, wherein the functional region is deflectable relative to the electrode in response to the force acting thereon.According to various embodiments, a microelectromechanical structure may include: a substrate; a functional structure and an electrode disposed at the substrate; wherein the functional structure includes a functional region deflectable relative to the electrode in response to a force applied thereto; and wherein the electrode includes or is formed from a single-crystal semiconductor material, e.g., single-crystal silicon carbide (SiC), single-crystal gallium nitride (GaN), or single-crystal silicon (Si).According to various embodiments, the functional region may be coupled to the substrate, e.g. in direct physical contact and / or by means of a fastening portion.According to various embodiments, a micromechanical structure may include: a substrate having a cavity; a single-crystal semiconductor layer (e.g. a single-crystal substrate sub-piece) having a first portion (also referred to as a fastening portion) and a second portion (also referred to as a suspended portion) (e.g. adjoining thereto); wherein the second portion adjoins the cavity and is coupled to the substrate by means of the first portion.According to various embodiments, the first portion may have a distance from the cavity.According to various embodiments, at least one region of the substrate and / or the second portion may be arranged between the first portion and the cavity.According to various embodiments, the micromechanical structure may further include: a functional structure including a functional region that is deflectable relative to the substrate (e.g. into the cavity) in response to a force acting thereon; wherein the second portion includes or is formed from the functional region.According to various embodiments, the micromechanical structure may further include: an electrode arranged at the substrate; a functional structure including a functional region deflectable relative to the electrode (e.g. into the cavity) in response to a force acting thereon; and wherein the electrode includes the second portion.According to various embodiments, the cavity may be arranged between and / or be adjacent to the electrode and the functional region.According to various embodiments, the second portion may include at least one of: silicon carbide and / or gallium nitride, a greater modulus of elasticity than the substrate; and / or a greater mechanical hardness than the substrate.According to various embodiments, the second portion may include at least one of the following: (e.g. single crystal) silicon carbide, (e.g. single crystal) gallium nitride, a greater modulus of elasticity than one of the following: polysilicon, the substrate and / or than 200 GPa (e.g. in a range from about 200 GPa to about 600 GPa), a greater mechanical hardness than one of the following: polysilicon, the substrate and / or than 20 GPa (e.g. in a range from about 20 GPa to about 50 GPa) and / or a greater (e.g. laterally extending) single crystal region than the substrate.According to various embodiments, the micromechanical structure may further include: an additional (e.g. polycrystalline) semiconductor layer (e.g. including or formed from silicon), which differs from the monocrystalline semiconductor layer in its modulus of elasticity and / or in its mechanical hardness; wherein the cavity is arranged between the monocrystalline semiconductor layer and the additional semiconductor layer and / or adjoins the latter.According to various embodiments, an electromechanical transducer may include: a substrate; a microelectromechanical structure in dual electrode configuration (e.g. a capacitive sensor structure); wherein the microelectromechanical structure comprises at least one free-suspended portion (e.g., a layer), wherein the at least one free-suspended portion may comprise at least one of: (e.g., single-crystal) silicon carbide, (e.g., single-crystal) gallium nitride, a greater elastic modulus than one of: polysilicon, the substrate, and / or than 200 GPa (e.g., in a range from about 200 GPa to about 600 GPa), a greater mechanical hardness than one of: polysilicon, the substrate, and / or than 20 GPa (e.g., in a range from about 20 GPa to about 50 GPa), and / or a greater (e.g., laterally extending) single-crystal region than the substrate.The freely suspended section can be configured according to the double electrode configuration, for example as part of an electrode and / or as part of a membrane and / or as part of a cantilever. For example, the dual electrode configuration may provide two cavities, at least one (e.g., both) of which are adjacent to the suspended portion. Alternatively or additionally, the dual electrode configuration may provide the suspended portion and two additional suspended portions, at least a first suspended portion of which is part of a first electrode, a second suspended portion of which is part of a second electrode and a third suspended portion of which is part of a functional region and / or is arranged between the first electrode and the second electrode. The free-hanging portion can adjoin a cavity of the substrate, for example.According to various embodiments, the electromechanical transducer may further comprise a mounting portion monolithically connected to the suspended portion and by means of which the at least one suspended portion is coupled (e.g. mounted) to the substrate.According to various embodiments, the at least one suspended portion may include or be formed from a substrate portion (e.g. the layer).According to various embodiments, an electromechanical transducer may include: a substrate; a microelectromechanical structure in dual electrode configuration (e.g. a capacitive sensor structure); wherein the microelectromechanical structure includes at least one substrate portion (e.g. a layer), wherein the substrate portion may include or be formed from (e.g. single crystal) silicon carbide and / or (e.g. single crystal) gallium nitride.According to various embodiments, the electromechanical transducer may include two electrodes, at least one electrode of which includes or is formed from the at least one freely suspended portion, e.g. the at least one substrate portion (e.g. the layer).According to various embodiments, the electromechanical transducer (e.g. a capacitive sensor) may comprise at least one functional region which is deflectable relative to the substrate in response to a force acting thereon; wherein the at least one freely suspended portion, e.g. the at least one substrate portion (e.g. the layer), comprises the functional region. Optionally, the at least one substrate section (e.g. the layer) can have the anchored section, by means of which the functional region is coupled to (e.g. fastened to) the substrate.According to various embodiments, the functional region may be coupled to the substrate, e.g. in direct physical contact and / or by means of an anchored portion (also referred to as attachment portion) of the substrate portion (e.g. the layer).According to various embodiments, the at least one free-hanging portion, e.g. the at least one substrate portion (e.g. the layer), may comprise or be formed from single-crystal silicon carbide.According to various embodiments, a method may include: forming a target separation layer in a single-crystalline substrate; separating the substrate along (e.g. in) the target separation layer such that a single-crystalline layer is divided from the substrate; and forming a micromechanical structure including the single-crystalline layer.According to various embodiments, a method may include: forming a target separation layer in a single-crystalline substrate; attaching the substrate to an additional substrate; wherein a substrate portion of the substrate is arranged between the target separation layer and the additional substrate; severing the substrate in the target separation layer; and forming a micromechanical structure including at least the substrate portion (and optionally the additional substrate and / or optionally an additional substrate portion of the substrate).According to various embodiments, a method for processing a substrate (having a monocrystalline region or formed therefrom) may include the following: severing the monocrystalline region into at least two subareas (of which, for example, at least a first subarea has a monocrystalline layer); and forming a micromechanical structure which has at least one subarea (also referred to as first subarea) of the two subareas.According to various embodiments, a method for processing a substrate may be configured, wherein the substrate comprises: a first main processing side and a second main processing side, which are opposite to each other; a single crystal region on the first main processing side (e.g. adjoining both main processing sides). The method may include: separating (e.g. severing) the substrate through the monocrystalline region and along the first main processing side into at least two substrate segments, of which at least one substrate segment (also referred to as first substrate segment) has a monocrystalline layer of the monocrystalline region; and forming a micromechanical structure which has the monocrystalline layer.According to various embodiments, the first substrate portion, e.g. the single crystal layer, may be patterned.According to various embodiments, the micromechanical structure may include a stiffening structure, the stiffening structure including the substrate subsection. Optionally, the substrate portion of the stiffening structure can be structured.According to various embodiments, the substrate portion of the micromechanical structure may include a suspension point of the micromechanical structure, i.e., a fixed contact point with the additional substrate.According to various embodiments, a method for forming a micromechanical structure may include: transferring at least one substrate portion (e.g. a single-crystal layer) from a first substrate to a second substrate; and forming a micromechanical structure including the at least one substrate portion (e.g. the single-crystal layer).According to various embodiments, the first substrate and the second substrate may differ in their chemical composition and / or in their crystallization type (i.e. polycrystalline or single crystalline). For example, the first substrate may be single crystalline and / or the second substrate may be polycrystalline.The single-crystal substrate portion (e.g., the single-crystal layer) may include or be formed from at least one of SiC, GaN, or Si.The transfer of the single-crystalline substrate portion (e.g. of the single-crystalline layer) can be effected by means of a smartcut process according to various embodiments.Before or after the transfer of the single-crystalline substrate portion (e.g. of the single-crystalline layer), the single-crystalline substrate portion (e.g. of the single-crystalline layer) can be altered, e.g. chemically and / or structurally. The changing can, for example, change the mechanical characteristic of the single-crystalline substrate portion (e.g. of the single-crystalline layer) (e.g. its strain and / or bias), and / or can change the electrical properties of the single-crystalline substrate portion (e.g. of the single-crystalline layer) (e.g. its electrical conductivity).According to various embodiments, the micromechanical structure may be provided in a dual electrode configuration or a single electrode configuration, e.g. a top-side single electrode configuration or bottom-side single electrode configuration.According to various embodiments, hydrophilic bonding may utilize that water molecules chemisorb on a hydrophilic surface (e.g. a substrate), thereby forming hydroxil groups (e.g. in silanol). If two surfaces which have chemisorbed water molecules are brought into physical contact with one another, polymerization of the hydroxyl groups begins (e.g. with liberation of water), for example already at room temperature. An optional annealing process (e.g., at a temperature in a range 110° C. from about to about 800° C.) may enhance this reaction and thus enhance the adhesion of the two surfaces to each other. The hydrophilic surface can be provided, for example, by means of an oxide layer, for example by means of a silicon oxide layer.According to various embodiments, a ratio (also referred to as aspect ratio) of the lateral extension of the free-hanging portion to the vertical extension of the free-hanging portion may be greater than approximately 1·10 3, e.g. greater than approximately 2·10 3, e.g. greater than approximately 4·10 3, e.g. greater than approximately 6·10 3.The lateral extent of the freely suspended section can correspond, for example, to the lateral extent (e.g. diameter) of the cavity or of the opening of the substrate, to which the freely suspended section adjoins. The vertical extent of the freely suspended section can correspond, for example, to the distance between two cavities between which the freely suspended section is arranged.For example, the lateral extent may be in a range from about 400 μm to about 1000 μm, e.g. in a range from about 600 μm to about 850 μm. Alternatively or additionally, the vertical extension may be in a range from about 100 nm to about 1000 nm, e.g. in a range from about 150 nm to about 350 nm. In other embodiments, the vertical extent may also be greater than 1 μm.For example, a membrane (e.g., a microphone) may have a membrane diameter of about 540 μm and a membrane thickness of about 330 nm, resulting in an aspect ratio of about 1.6·10 3.According to various embodiments, the suspended portion may provide a deflectable region. The free-hanging portion may have a lower stiffness and / or bending strength than the first electrode and / or than the second electrode. The stiffness can describe the elastic deformation (e.g. deflection) per applied force. The bending strength can describe the deflection per applied bending moment.According to various embodiments, the micromechanical structure may include at least two free-hanging portions, of which a first free-hanging portion is formed using a substrate section and has a greater modulus of elasticity and / or a greater mechanical hardness than the second free-hanging portion of the two free-hanging portions. The first free-hanging portion may, for example, comprise (e.g. monocrystalline) SiC or be formed therefrom and / or comprise (e.g. monocrystalline) gallium nitride or be formed therefrom. Alternatively or additionally, the first free-hanging portion may have a larger (e.g. laterally extended) single-crystalline region than the second free-hanging portion and / or than the substrate.Exemplary embodiments of the invention are illustrated in the figures and are explained in more detail below.They show FIGS. 1A to 1C each show a micromechanical structure in a method according to various specific embodiments; FIGS. 2A to 2C each show a micromechanical structure in a method according to various specific embodiments; FIGS. 3A to 3C each show a micromechanical structure in a method according to various specific embodiments; FIGS. 4A to 4C each show a micromechanical structure in a method according to various specific embodiments; FIGS. 5A to 5D each show a micromechanical structure in a method according to various specific embodiments; FIGS. 6A to 6C each show a micromechanical structure in a method according to various specific embodiments; FIGS. 7A and 7B each show a micromechanical structure in a method according to various specific embodiments; FIGS. 8A and 8B each show a micromechanical structure in a method according to various specific embodiments; FIGS. 9A and 9B each show a micromechanical structure in a method according to various specific embodiments; FIG. 10 shows a micromechanical structure in a method according to various specific embodiments; FIGS. 11A and 11B each show a micromechanical structure in a method according to various specific embodiments; FIGS. 12A and 12B each show a micromechanical structure in a method according to various specific embodiments; FIGS. 13A and 13B each show a micromechanical structure in a method according to various specific embodiments; FIG. 14 shows a micromechanical structure in a method according to various specific embodiments; FIGS. 15A and 15B each show a micromechanical structure in a method according to various specific embodiments; FIG. 16 shows a micromechanical structure in a method according to various embodiments; and FIG. 17 illustrates a method according to various embodiments.In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "front", "rear", etc. is used with reference to the orientation of the figure(s) described. Since components of embodiments may be positioned in a number of different orientations, the direction terminology is for the purpose of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It should be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically stated otherwise. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.The term "exemplary" is used herein to mean "serving as an example, instance, or illustration.". Any embodiment or configuration described herein as "exemplary" is not necessarily to be considered preferred or advantageous over other embodiments or configurations.The term "over" in relation to deposited material formed "over" a side or surface may be understood according to various embodiments as the deposited material being formed "directly on", e.g. in direct (e.g. physical or adjacent) contact with, said side or surface. The term "over" in relation to a deposited material formed "over" a side or surface may be understood according to various embodiments as the deposited material being formed "indirectly on" said side or surface, wherein one or more additional layers are or are arranged between said side or surface and the deposited material. The deposition of the material can be effected, for example, by means of chemical vapor deposition (CVD) or physical vapor deposition (PVD).The term "laterally" or "laterally" with respect to the "lateral" extension of a structure (or a substrate, a wafer or a carrier) or "laterally" adjoining thereto, may be used according to various embodiments to denote an extension or a positional relationship along a surface of a substrate, a wafer or a carrier. That is, a surface of a substrate (for example, a surface of a carrier or a surface of a wafer) may serve as a reference, which is generally referred to as the main processing surface of the substrate (or the main processing surface of the carrier or wafer). Further, the term "width" used with respect to a "width" of a structure (or structural element) may be used herein to refer to the lateral (or lateral) extension of a structure.Further, the term "height" used with respect to a height of a structure (or feature) may be used herein to refer to the extension of a structure along a direction perpendicular to the surface of a substrate (e.g., perpendicular to the main processing surface of a substrate), i.e., a vertical extension. The term "thickness" used with respect to a "thickness" of a layer may be used herein to refer to the spatial extent of the layer perpendicular to the surface of the carrier (material) on which the layer is deposited, i.e. a vertical extent. If the surface of the carrier is parallel to the surface of the substrate (for example to the main processing surface), the thickness of the layer applied to the carrier may be equal to the height of the layer. Further, a "vertical" structure may refer to a structure extending in a direction perpendicular to the lateral direction (e.g., perpendicular to the main processing surface of a substrate), and a "vertical" extension may refer to an extension along a direction perpendicular to a lateral direction (e.g., an extension perpendicular to the main processing surface of a substrate).In the context of this description, the terms "connected", "connected" and "coupled" are used to describe both a direct and an indirect connection (e.g. ohmic and / or electrically conductive, e.g. an electrically conductive connection), a direct or indirect connection and a direct or indirect coupling. In the figures, identical or similar elements are provided with identical reference numerals, as appropriate. A coupling can be understood as a mechanical coupling.The term "formed therefrom" in relation to a first structure (e.g. body, layer, portion) being formed from a second structure (e.g. body, layer, portion) can be understood as the second structure being used for forming the first structure, i.e. the first structure having at least a part of the second structure. To form the first structure, the second structure can optionally be processed (e.g. chemically, electrically and / or structurally modified), for example this material can be removed and / or added, this formed or cleaned. Alternatively, the second structure can be transformed into the first structure unchanged.In the context of this description, a metal (also referred to as metallic material) may include (or be formed from) at least one metallic element (i.e. one or more metallic elements), for example at least one element from the following group of elements: copper (Cu), iron (Fe), titanium (Ti), nickel (Ni), silver (Ag), chromium (Cr), platinum (Pt), gold (Au), magnesium (Mg), aluminum (Al), zirconium (Zr), tantalum (Ta), molybdenum (Mo), tungsten (W), vanadium (V), barium (Ba), indium (In), calcium (Ca), hafnium (Hf), samarium (Sm), silver (Ag) and / or lithium (Li). Furthermore, a metal may include or be formed from a metallic compound (e.g. an intermetallic compound or an alloy), e.g. a compound of at least two metallic elements (e.g. from the group of elements), such as e.g. bronze or brass, or e.g. a compound of at least one metallic element (e.g. from the group of elements) and at least one nonmetallic element (e.g. carbon), such as e.g. steel. Optionally, the metal can have alloying elements (the mass fraction of which is, for example, less than 10%, e.g. individually or in total), e.g. chromium, silicon, molybdenum, nickel, vanadium, carbon, manganese, phosphorus, sulfur, tin, zinc.Microphones and / or microspeakers, which are realized using chip technology, are usually produced using silicon technology. Micromachined silicon microphones are capacitive transducers with a flexible diaphragm moving in the sound field and a static perforated electrode called a backplate or electrode. According to the concept of overpressure, the membrane may be or may be exposed to pressure differences of up to 10 bar. In such cases, conventional diaphragms fail because their breaking strength or a maximum mechanical load (e.g., force or stress) which the diaphragm can withstand (breaking resistance) is exceeded.According to various embodiments, a micromechanical system or a microelectromechanical system may be used to provide an actuator or sensor, for example.According to various embodiments, an electromechanical (e.g. sensory or actuator) transducer (e.g. sound transducer) is provided, which comprises a single-crystal substrate section. The actuator transducer complementary to the sensory transducer may comprise, for example, a microspeaker which must be actuated to effect a stroke which produces an air displacement and hence a sound pressure.A functional structure of a micromechanical structure, such as a diaphragm, may be or will be clamped, i.e. fixed to an anchored (i.e. clamped, embedded and / or fixed) portion (also referred to as a fastening portion) and be vibratable or deflectable in the protruding portion. The deflectable region may be part of the cantilever portion (also referred to as a cantilevered portion). For example, the anchored portion and the protruding portion may be (e.g. monolithically and / or adjacently) monocrystalline and / or be formed by processing the monocrystalline substrate piece.A micromechanical system (MMS) or microelectromechanical system (MMS with electrical component) can generally be used as actuator (actuator) or sensor. For example, the system can be configured to convert between electrical energy and mechanical energy.According to various embodiments, it has been recognized that integration of SiC into a microelectromechanical system (such as a microphone) provides a plurality of possibilities. As compared with poly-Si, SiC has higher mechanical hardness and higher Young's modulus (also referred to as modulus of elasticity or Young's modulus). For example, poly-Si may have a mechanical hardness of about 12.5 gigapascals (GPa) and an elastic modulus of about 180 GPa. On the other hand, SiC may have a mechanical hardness in a range of about 20 GPa to about 50 GPa and an elastic modulus in a range of about 200 GPa to about 600 GPa. Optionally, according to various embodiments, by introducing impurities into the SiC, its E-modulus can be reduced, for example to 500 GaP or less (and / or more than 200 GPa).The higher hardness properties of SiC may help protect the micromechanical structure (e.g. its membrane) from damage, e.g. from membrane damage caused from the outside. In addition to the mechanical hardness, the modulus of elasticity and an optional prestress of the SiC layer (illustratively internal stress, which can be artificially induced, for example) can influence the mechanical properties of the micromechanical structure. In the case of small deflections of the diaphragm, the layer stress (layer stress) can dominate the deflection behavior and the influence of the Young's modulus can increase with increasing deflection of the diaphragm.In general, according to various embodiments, the SiC membrane may be made thinner than a membrane made of poly-Si without losing robustness. A thinner diaphragm may allow for greater deflection so that smaller pressure differences may be detected with good signal level. In other words, a thinner membrane may promote greater sensitivity and / or SNR.The mechanical properties (e.g. oscillation properties and / or prestressing) and the electrical properties (e.g. electrical conductivity) of SiC can optionally be modified subsequently, e.g. by means of the implantation of nitrogen (N 2).The inert chemical properties, such as hydrophobicity (low adhesion tendency), of the SiC material may have a tendency to particle contamination and / or reduce the risk of membrane adhesion.Optionally, the single crystal material (e.g. semiconductor material), e.g. single crystal SiC, may be used not only as membrane material, but also as stabilization under a poly-Si membrane. This makes it possible to combine a conventional method of layer modification of poly-Si with the mechanical properties of the single-crystalline material (e.g. SiC). According to various embodiments, SiC may be provided as a membrane material or as a stabilizer of a polysilicon membrane. In contrast to a conventional diaphragm, SiC may be formed thinner and / or may undergo larger deflections without being damaged.According to various embodiments, "monocrystalline" or "single crystal" with respect to a crystallization type, a material or a body (e.g. a substrate, its substrate portion or a layer) may be understood to mean that its building blocks (i.e. atoms, ions or molecules) form a substantially continuous, homogeneous (illustratively macroscopic) crystal lattice. In other words, the single-crystal crystal lattice can have a uniform orientation (also referred to as main orientation), i.e. the spatially averaged orientation of the crystal building blocks can be substantially the same.This distinguishes the single crystal type of crystallization from a polycrystalline type of crystallization, twinned type of crystallization, or an amorphous material (noncrystalline material). The amorphous material may have an arbitrary orientation and / or arrangement of the devices. The polycrystalline crystallization type and / or the twinned crystallization type may comprise or be formed from a multiplicity (illustratively microscopic) of crystalline grains (crystallites) which are separated from one another by grain boundaries.Generally, the differentiation in the crystallization type may be understood as distinguishing in the principal orientation of the crystal structure and / or as distinguishing in the mean deviation from the principal orientation of the crystal structure. A single crystal type of crystallization may have a lower mean deviation from the main orientation and / or a lower spatial density at grain boundaries and / or crystallites than a polycrystalline type of crystallization or than a twinned type of crystallization.According to various embodiments, a substrate (e.g. comprising the single-crystal sub-region) may be processed to form one or more functional structures, e.g. separated from one another or interconnected with one another. A plurality of interconnected functional structures can form, for example, an electronic circuit, e.g. a sensor array. In general, one or more micromechanical structures may be formed and / or integrated in the substrate (also referred to as chips or semiconductor chips).Each or the micromechanical structure may have a functional structure. The functional structure can be arranged in a part of the substrate and can comprise at least one functional region (exactly one functional region or a plurality of functional regions), such as, for example, at least one membrane or at least one cantilever. The at least one functional region may be configured for deflection, e.g. in response to a mechanical signal or an electrical signal, e.g. in power electronics (e.g. using power components).According to various embodiments, a micromechanical structure (also referred to as an integrated micromechanical structure or micromechanical chip) may be singulated from the substrate (or from a semiconductor wafer) by removing material from a kerf (also referred to as a kerf) of the substrate (also referred to as dicing or slicing the substrate). For example, removal of material from the cut line of the substrate may be accomplished by scribing and breaking, cleaving, blade dicing (separation / separation), plasma dicing (separation / separation), laser dicing, or mechanical sawing (e.g., using a dicing saw). After the separation of the micromechanical chip, the latter can be electrically contacted and subsequently encapsulated (e.g. closed or semi-open), e.g. by means of a molding material and / or into a chip carrier (also referred to as chip package) which is suitable for use in an electronic device. For example, the micromechanical chip may be connected by means of wires within the chip carrier and / or the chip carrier may be soldered on a printed circuit board and / or on a lead frame.The term semiconductor material may be understood as a chemical composition comprising or formed from a semiconducting base material and / or being semiconducting in an undoped state, i.e. having an electrical conductivity in a range from about 10 -6 Siemens / meter to about 10 6 Siemens / meter. During the processing (processing) of the semiconductor material, the semiconducting base material can be or will be doped, for example, in sections, which increases its electrical conductivity in the doped locations (e.g. above 10 6 siemens / meter). The semiconductor material or the semiconducting base material can comprise or be formed from, for example, an elementary semiconductor (e.g. silicon or germanium) or a compound semiconductor (e.g. silicon carbide or SiGe).According to various embodiments, a substrate (e.g. its substrate portions) or a semiconductor region (e.g. the single crystal region), may include or be formed from a semiconductor material (e.g. the semiconducting base material) of one type or different types, including Group IV semiconductors (e.g. silicon or germanium), compound semiconductors, e.g. Group III-V compound semiconductors (e.g. gallium arsenide), Group III semiconductors, Group V semiconductors or semiconducting polymers. In several embodiments, the substrate and / or the semiconductor region (e.g., its circuit region) may be formed of silicon (doped or undoped). In several alternative embodiments, the substrate may be a silicon-on-insulator (SOI) wafer (e.g., the second substrate). Alternatively, any other suitable semiconductor material may be used for the substrate and / or the semiconductor region, for example a semiconductor compound (semiconducting chemical compound) such as gallium phosphide (GaP), indium phosphide (InP), silicon carbide (SiC) or gallium nitride (GaN), but also any suitable ternary semiconductor compound or quaternary semiconductor compound such as indium gallium arsenide (InGaAs).Illustratively, the method provided according to various embodiments may result in a micromechanical structure, the monocrystalline layer of which is illustratively chemically purer, has fewer twin boundaries and a greater thickness, e.g. more than 10 nanometers (uppermost boundary, which is possible by means of conventional carbonization). Furthermore, the monocrystalline layer provided can be stress-neutral, i.e. can be produced without a prestress, which increases the space for subsequent adaptation.FIGS. 1A, 1B and 1C each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).The method may include, in 100 a: providing a substrate 102 including or formed from a single-crystalline region 104 (also referred to as single-crystal region 104), e.g. providing a single-crystalline substrate 102. The substrate 102 may have two main processing sides 102 o, 102 uwhich are opposite to each other. For example, the substrate 102 and / or the single crystal region 104 may include or be formed from a single crystal semiconductor material, e.g. single crystal GaN, single crystal SiC and / or single crystal Si. The single crystal SiC may be in a hexagonal crystal configuration (for example, a 4H configuration), for example. The hexagonal crystal configuration may be particularly low at twin boundaries. In other words, the substrate 102 and / or the single crystal region 104 can comprise or be formed from single-crystal, hexagonal SiC. The 4H configuration may include or be formed from a mixture of a purely hexagonal crystal portion and a purely cubic crystal portion.The method can furthermore comprise, in 100 b: severing the substrate 102 along a (e.g. first) main processing side 102 o(e.g. parallel thereto) into at least two substrate segments 102 a, 102 b, each of which has a single-crystalline partial region 104 a, 104 bof the single-crystal region 104 or is formed therefrom, e.g. into at least two single-crystalline substrate segments 102 a, 102 b. For example, the severing can comprise: severing the single crystal region 104 into two single crystal sub-regions 104 a, 104 b.The method may further include, in 100 c: forming a micromechanical structure 106 including a substrate portion 102 a(also referred to as first substrate portion 102 a) of the at least two substrate portions 102 a, 102 bor at least one single-crystalline sub-region 104 a(also referred to as first sub-region 104 a) of the two single-crystalline sub-regions 104 a, 104 b.For example, the first substrate subsection 102 a, which is used to form the micromechanical structure 106, may have a monocrystalline layer 104 aor be formed therefrom (or at least from a part thereof). Alternatively or additionally, the two substrate sections 102 a, 102 bmay differ in their vertical extension 102 d, 112 d, e.g. the ratio of the vertical extensions 102 d, 112 dmay be more than about 10, e.g. more than about 100, e.g. more than about 1000. For example, the first substrate portion 102 amay have a vertical extension 102 d(i.e. extension transverse to the main processing side 102 o) smaller than the other substrate portion 102 b(also referred to as second substrate portion 102 b), e.g. less than about 10% of the vertical extension 112 dof the second substrate portion 102 b), e.g. less than about 1% of the vertical extension 112 dof the second substrate portion 102 b, e.g. less than about 0.1% of the vertical extension 112 dof the second substrate portion 102 b. For example, the other substrate subsection 102 bmay have a substrate residue or be formed therefrom (or at least from a part thereof).For example, the vertical extension 102 dof the first substrate portion 102 amay be greater than about 10 nm (nanometers), e.g. greater than about 50 nm, e.g. greater than about 100 nm, e.g. greater than about 150 nm, e.g. greater than about 200 nm. Alternatively or additionally, the vertical extension 102 dof the first substrate portion 102 amay be less than about 1 μm (micrometer), e.g. less than about 660 nm. For example, the vertical extension 102 dof the first substrate portion 102 amay be more than 100 nm (e.g. less than about 1 μm), e.g. in a range from about 150 nm to about 660 nm, e.g. in a range from about 280 nm to about 660 nm, e.g. less than 330 nm, e.g. less than 200 nm.A layer may be understood to mean a planar structure having a vertical extent 102 dof less than approximately 10 μm, e.g. less than approximately 1 μm, e.g. less than approximately 0.1 μm, e.g. less than approximately 0.01 μm. For example, the or each substrate portion 102 a, 102 b(divided from the substrate 102) may be layered, i.e. have a vertical extension 102 dof less than about 10 μm, e.g. less than about 1 μm, e.g. less than about 0.1 μm, e.g. less than about 0.01 μm.A substrate residue can be understood to mean a planar structure which has a vertical extent 102 dof more than approximately 10 μm, for example more than approximately 100 μm, for example more than approximately 250 μm, for example more than approximately 500 μm. Additional substrate segments can optionally be divided from the substrate residue by severing the latter.Optionally, the method in 100 cmay include: forming an additional micromechanical structure including the second substrate portion 102 bor at least the second sub-region 104 bthereof. The second substrate section 102b may be previously divided from the substrate residue by cutting it. Illustratively, the substrate 102 may include more than two substrate portions, which may be successively separated from the substrate 102. Each of the substrate portions of the substrate 102 being separated may be implemented in a micromechanical structure. Optionally, two substrate sections 102 a, 102 bmay be implemented in the same micromechanical structure. For example, first substrate subsection 102 amay provide the functional region of micromechanical structure 106 and / or second substrate subsection 102 bmay provide an electrode of micromechanical structure 106.Forming the micromechanical structure may optionally include in 100 c: processing (e.g. structuring, thinning, doping) the first substrate portion 102 a. In other words, a structure of micromechanical structure 106 formed from first substrate subsection 102 amay include processed first substrate subsection 102 a.FIGS. 2A, 2B and 2C each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).In 200 a, the substrate can have a target separating layer 202, by means of which the two substrate segments 102 a, 102 bare connected to one another. The target separation layer 202 can be extended through the single-crystalline region 104, for example. The target separation layer 202 may include the semiconductor material of the substrate 102 and may include an impurity in a greater impurity concentration than the first and / or the second substrate portion 102 a, 102 b. Alternatively or additionally, the target separation layer 202 may have a plurality of imperfections (e.g., lattice defects, pores, or capillaries). Then, the target separation layer 202 may have a greater impurity density than the first and / or the second substrate portion 102 a, 102 b. For example, the target separation layer 202 may have a greater porosity than the first and / or the second substrate portion 102 a, 102 b.For example, providing 100 aof the substrate 102 in 200 acan comprise: forming the target separation layer 202 by changing a chemical composition of the first substrate 102 between the two substrate sections 102 a, 102 b.Furthermore, in 200 b, the method can comprise: severing the substrate 102, wherein the severing takes place by a cohesion of the desired separating layer 202 being canceled. The cohesion of the desired separating layer 202 can be canceled by means of (e.g. chemical, thermal or mechanical) processing of the substrate 102. For example, each substrate portion of the two substrate portions 102 a, 102 bmay be more resistant (e.g., more temperature resistant) to processing than the target separation layer 202. In other words, the target separation layer 202 may have a greater resistance to processing than each substrate section of the two substrate sections 102 a, 102 b.Greater durability results in a slower change, e.g., no change. For example, a structure (e.g. a region or a layer) and / or a material can be changed less and / or more slowly by the processing the greater its resistance. The consistency may be related to a particular type of processing and / or may differ from one another for different types of processing.The less mechanically resistant structure (e.g. region or layer) and / or the less mechanically resistant material may have, for example, a lower fracture strength, fracture force, tensile strength and / or mechanical hardness than the more mechanically resistant structure (e.g. region or layer) and / or the more mechanically resistant material. The less chemically resistant structure (e.g. region or layer) and / or the less chemically resistant material may, for example, have a greater chemical reactivity with a chemical processing agent than the more chemically resistant structure (e.g. region or layer) and / or the more mechanically resistant material.Durability may be reduced, for example, by increasing a surface area. Thus, for example, a chemically reactive etchant can be provided with a larger surface area on which the etchant can attack. Alternatively or additionally, a resistance may be increased by increasing a mechanical hardness and / or breaking force and / or reducing a chemical reactivity to the etchant (also referred to as passivation). Chemical reactivity may describe the ability of a material to undergo a chemical reaction, e.g., the rate at which the chemical reaction occurs or the energy threshold necessary to initiate rectification (also referred to as activation energy). For example, the chemical reaction may cause formation of pores.According to various embodiments, temperature-stable in connection with a temperature can be understood to mean that a structure or a material can be loaded at least up to the temperature without losing its function and / or shape. For example, the structure or the material can undergo no or hardly any chemical reactions with its environment at least up to the temperature and / or remain chemically stable. For example, the structure or material may maintain its aggregate state and / or chemical composition at least up to temperature. For example, the structure or material may maintain its shape and / or volume (i.e., without structurally changing) at least up to temperature. For example, the temperature up to which the structure or material is temperature stable may be a temperature at which the state of aggregation of the structure or material changes, e.g., a melting temperature, or may be a transition temperature, e.g., a glass transition temperature.According to various embodiments, the severing can comprise subtractive processing, such as, for example, severing, removal or machining.The removal can be understood as a group of (thermal and / or chemical) processing processes which belong to the main group of separation. This group of machining processes, in contrast to machining or dicing, can separate individual workpiece layers or parts in a non-mechanical manner. The removal may include, for example: thermal removal (e.g. laser beam processing, plasma etching), chemical removal (e.g. etching), electrochemical removal (e.g. electroerodation). The severing can be carried out, for example, by removing the desired separating layer 202, for example by means of thermal removal (for example laser beam processing, plasma etching), chemical removal (for example etching), water jet cutting and / or electrochemical removal (for example electroerodation). The severing can be carried out, for example, by the desired separating layer 202 being at least partially removed by means of an etchant. Thus, a connection of the two substrate sections 102 a, 102 bcan be released.The dividing may include separating the substrate 102 into multiple parts, e.g., without chip formation, e.g., by tearing, by breaking, and / or by cutting. The severing can be carried out, for example, by dividing the substrate 102, for example by tearing or breaking the substrate 102 in the desired separating layer. For example, a mechanical force (e.g., a tensile force) exceeding the breaking force of the target separation layer may be transmitted to the target separation layer.For example, forming the target separation layer 202 in 200 acan include: changing a chemical composition between the two substrate sections 102 a, 102 b. In other words, an interface 202 (also referred to as interface 202) between the two substrate sections 102 a, 102 bmay be chemically altered. For example, by means of the modification, a resistance of the substrate 102 in the modified boundary layer 202 between the two substrate sections 102 a, 102 bto severing can be reduced.For example, forming the target separation layer 202 in 200 cmay include: changing a chemical composition between the two substrate portions 102 a, 102 bby means of ion implantation 204 (also referred to as doping the boundary layer 202). Optionally, in 200 c, the method may include: altering a chemical composition of the first substrate portion 102 aby means of ion implantation 204 (also referred to as doping the first substrate portion 102 a). In other words, the desired separating layer 202 can be formed between the two substrate segments 102 a, 102 bby means of a first ion implantation 204 and the first substrate segment 102 acan be changed by means of an optional second ion implantation 204. Optionally, the first ion implantation 204 and the second ion implantation 204 may differ, e.g. in at least the implanted material and / or the implantation depth of the implantation energy.By means of the ion implantation 204, an impurity (e.g. a chemical element) in the form of ions of the impurity may be introduced into the substrate 102 and / or the first substrate portion 102 a. For example, a concentration (also referred to as impurity concentration) of the impurity may be increased in the changed portion, e.g., in the barrier layer 202 and / or in the first substrate portion 102 a. Optionally, a reaction of the impurity with the semiconductor material of the boundary layer 202 may be stimulated, e.g. by means of a thermal treatment.For example, by means of the ion implantation 204, an impurity concentration (i.e. a number of atoms of the impurity) may be formed (e.g. increased) in the boundary layer 202 or in the first substrate section 102 a, for example of more than in the second substrate section 102 band / or of more than about 10 15 atoms per cubic centimeter (atoms / cm 3), e.g. of more than about 10 16 atoms / cm 3, e.g. of more than about 10 17 atoms / cm 3, e.g. of more than about 10 18 atoms / cm 3, e.g., up to about 10 19 atoms / cm 3. The ion implantation 204 may make it possible to provide the position and / or thickness of the desired separating layer 202 with a clearly as small a deviation from the specification as possible.Changing the chemical composition of the boundary layer 202 between the first substrate section 102 aand the second substrate section 102 bmay include changing a mechanical characteristic of the boundary layer 202, e.g. reducing its mechanical breaking strength and / or increasing its porosity. For example, at least hydrogen can be introduced into the boundary layer 202 by means of the first ion implantation 204. In other words, the impurity introduced into the boundary layer (also referred to as second impurity) may include or be formed from at least hydrogen. In other words, the second impurity may include or be formed from hydrogen. Hydrogenation can optionally be carried out, i.e. the addition of hydrogen to the chemical element or elements or the compound thereof from which the boundary layer 202 is composed.Alternatively or additionally, imperfections (e.g., lattice defects, pores, or capillaries) may be formed in the boundary layer 202, e.g., by structural modification of the boundary layer 202. After the altering, the boundary layer 202 may have a greater impurity density than the first and / or second substrate portion 102 a, 102 b. For example, the target separation layer 202 may have a greater porosity than the first and / or second substrate portion 102 a, 102 b. The impurity density may refer to the number of impurities (e.g., pores) per volume, i.e., a spatial density. The defects may be artificially generated to adjust the durability. The imperfections can reduce the mechanical resistance to severing.Altering the chemical composition of the first substrate portion 102 amay include altering, e.g. reducing, a mechanical characteristic (e.g. mechanical hardness, modulus of elasticity and / or mechanical stiffness) and / or electrical characteristic (e.g. electrical conductivity or electrical resistance) of the first substrate portion 102 a. Thus, for example, the mechanical properties of the functional structure formed later or the electrical properties of an electrode formed later therefrom can be adapted to predefined requirements. For example, by means of the optional second ion implantation 204, at least nitrogen and / or phosphorus can be introduced into the first substrate portion 102 a. In other words, the impurity (also referred to as second impurity) introduced into the first substrate portion 102 amay include or be formed from at least nitrogen and / or phosphorus.Illustratively, the first ion implantation 204 may be performed through the first single-crystal substrate portion 102 a. Alternatively or additionally, the second ion implantation 204 can be carried out into the first monocrystalline substrate portion 102 a.FIGS. 3A, 3B and 3C each illustrate a method according to various embodiments in a schematic side view or cross-sectional view.The method may include, in 300 a: attaching the substrate 102 (also referred to as first substrate 102), e.g. with the first main processing side 102 o, to an additional substrate 302 (also referred to as second substrate 302) before the severing. For example, the first substrate section 102 amay be attached to the second substrate 302.The second substrate 302 may be different from the first substrate 102 in at least one chemical composition and / or in at least one type of crystallization. For example, the first substrate may have a greater melting temperature than the second substrate 302 and / or greater than 900° C. Alternatively or additionally, the second substrate 302 may include or be formed from a semiconductor material (e.g., Si), an insulator (i.e., an electrically insulating material such as SiO 2), a ceramic, a metal (e.g., tungsten or molybdenum).The fastening can comprise, for example, in 300 ato connect the first substrate 102 and the second substrate 302 to one another, for example by means of an adhesive, by means of bonding (for example by means of hydrophilic bonding, anodic bonding and / or thermal bonding) and / or by means of laser beam welding. The bonding and / or the laser beam welding can form a non-detachable connection. The welding can be effected by means of local heat supply, e.g. until the first substrate 102 and / or the second substrate are locally melted, and can optionally have an additional force effect (pressure) to be exerted thereon, which forces the first substrate 102 and the second substrate 302 against one another. Bonding may be performed by a chemical reaction of the first substrate 102 and / or the second substrate 302 with each other, which is initiated at a temperature below its melting temperature. Optionally, the first substrate 102 and / or the second substrate 302 may be heated, e.g., to a temperature in a range 100° C. from about to about 700° C.The fastening can take place in 300 a, for example, by means of a materially bonded connection. The cohesive connection can be understood as a connection in which the connection partners are held together by atomic or molecular forces. The cohesive connection can be a non-detachable connection (also referred to as an irreversible connection), i.e. it can only be canceled by destroying the connection partners. The material connection can comprise: bonding, welding and / or adhesive bonding. For example, a non-detachable compound can be formed by chemisorption. According to various embodiments, the non-detachable cohesive connection can have an atomic-cohesive connection or be formed therefrom, i.e. be held together by means of atomic forces (e.g. by means of chemical bonds between the connection partners), e.g. by means of strong atomic forces (such as, for example, in the case of chemisorption).For example, the bonding of the first substrate 102 and the second substrate 302 to each other may be performed by means of an adhesion layer 304 (e.g. hydrophilic), as will be described in detail with reference to 300 b. The adhesion layer 304 may be disposed between the first substrate 102 and the second substrate 302.For example, a force (also referred to as adhesion force) with which the first substrate 102 and the second substrate 302 are fastened to each other, e.g., bonded to each other, may be greater than a breaking force of the target separation layer 202. For example, the bond (e.g., adhesion layer 304) between the two substrates 102, 302 may impart a force therebetween that is greater than their breaking force or the breaking force of the target release layer 202. In terms of the area of the joint, the breaking force may correspond to the tensile strength (in force per area). Clearly, a non-detachable connection can be provided which provides a force between the two substrates 102, 302 which is greater than their breaking force. The breaking force can be understood as the force required to break or tear the component.In other words, the bond between the first substrate 102 and the second substrate 302 may have a greater resistance to severing than the target separating layer 202.The attachment of the first substrate 102 to the second substrate 302 and the subsequent severing of the first substrate 102 can also be referred to as transferring the first substrate section 102 a.Furthermore, in 300 a, the method may include severing the substrate 102, wherein the first substrate portion 102 ais or remains attached to the second substrate 302.In 300 b, the substrate 102 may include an adhesion layer 304. For example, providing the substrate 102 in 300 bmay include: forming the adhesion layer 304 on the first main processing side 102 o. The adhesion layer 304 may be formed, for example, over (e.g. in physical contact with) the first substrate portion 102 a, e.g. by arranging a (e.g. hydrophilic) material (also referred to as adhesion material) from which the adhesion layer 304 is to be formed over the first substrate portion 102 a. The (e.g. dielectric) adhesion material can be arranged by means of a coating process, e.g. by means of chemical vapor deposition (CVD) or physical vapor deposition (PVD). The adhesion material may include or be formed from an oxide and / or a dielectric, e.g. a semiconductor oxide, e.g. silicon oxide.Alternatively, for forming the adhesion layer 304, a portion of the substrate 102 on the first main processing side 102 omay be chemically modified, e.g. converted (e.g. oxidized), wherein the adhesion layer 304 is formed from the chemically modified material of the substrate 102 (e.g. an oxide).For example, the adhesion layer 304 may include or be formed from an oxide (e.g. of the semiconductor material of the substrate 102), e.g. a semiconductor oxide such as silicon oxide (SiO 2-x, with 2>x≥0).For example, the fastening in 300 acan be effected by means of the adhesion layer 304, e.g. by heating the adhesion layer. For this purpose, the adhesion layer 304 can be brought into physical contact with the additional substrate. For example, the adhesion layer 304 may be in physical contact with the first substrate portion 102 a.Optionally, in 300 b, the method may include: altering a chemical composition of the first substrate portion 102 afixed to the second substrate 302 by means of the second ion implantation 204 (also referred to as doping the first substrate portion 102 a). The second ion implantation 204 may be configured as in 200 c.FIGS. 4A, 4B and 4C each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 400 a: exposing (e.g. mechanically releasing) at least one portion 404 (also referred to as exposed portion 404) of the first substrate piece 102 a, e.g. by removing a part of the second substrate 302 and / or by removing a remaining residue of the adhesion layer 304, e.g. respectively on opposite sides. The exposing may include forming an opening 302 o, e.g., a through opening 302 o(i.e., an opening 302 oextending through the substrate) in the second substrate 302. The opening 302 omay include or be formed from a cavity of the second substrate 302, for example.For example, micromechanical structure 106 may include an electrode including substrate piece 102 a, as described in greater detail below. Alternatively or additionally, micromechanical structure 106 may include a diaphragm including substrate piece 102 a, as described in greater detail below.The micromechanical structure 106, e.g. its first substrate piece 102 a, may have a first portion 402 (also referred to as suspension portion 402 or fastening portion 402) and a second portion 404 (e.g. adjoining thereto) (also referred to as free-hanging portion 404). The suspended portion 404 may be attached (e.g., suspended) to the second substrate 302 via the attachment portion 402.The free-hanging portion 404 can be exposed, for example, on mutually opposite sides (e.g. on the side facing the second substrate 302 and the side facing away therefrom accordingly).The suspended portion 404 may include or be formed from a portion of the first substrate piece 102 a(e.g. its single-crystalline sub-region 104 a). Alternatively or additionally, the fastening portion 402 can have or be formed from a portion of the first substrate piece 102 a(e.g. its single-crystalline subregion 104 a). For example, the first substrate piece 102 a(e.g. its single-crystal sub-region 104 a) may extend from the suspension of the micromechanical structure 106 into the freely suspended part of the micromechanical structure 106.For example, the suspended portion 404 and the attachment portion 402 may be monolithically connected (e.g., single crystal).For example, the free-hanging portion 404 (e.g. in the case of a membrane 408) may have a thickness 404 dof less than about 1 μm (micrometer), e.g. less than about 660 nm, and / or of more than 10 nm (e.g. greater than about 50 nm, e.g. greater than about 100 nm, e.g. greater than about 150 nm, e.g. greater than about 200 nm), e.g. in a range from about 150 nm to about 660 nm.For example, the free-hanging portion 404 (e.g. in the case of a cantilever 410) may have a thickness 404 dof less than about 5 μm (e.g. less than about 3 μm, e.g. less than about 1 μm, e.g. less than about 0.5 μm) and / or of more than 10 nm (e.g. greater than about 50 nm, e.g. greater than about 100 nm, e.g. greater than about 150 nm, e.g. greater than about 200 nm), e.g. in a range from about 2 μm to about 4 μm, e.g. about 3 μm.Forming micromechanical structure 106 may optionally include, in 400 a: thinning and / or planarizing first substrate portion 102 aor at least first sub-region 104 a.The formation of micromechanical structure 106 may include, in 400 b: forming a membrane 408 which includes or is formed from first substrate subsection 102 aor at least first subregion 104 a. The membrane 408 may be configured to deflect in a central region (also referred to as a functional region) of the suspended portion 404 that is, e.g., spaced from the second substrate 302, e.g., above the opening 302 o. During deflection, a perimeter area of the suspended portion 404 (disposed at or near the second substrate 302) of the membrane 408 may be (e.g., immovably) held by the attachment portion 402 (also referred to as a seat or restraint).The membrane 408 can be understood as a planar structural element, such as a plate, which is anchored to one or more circumferential regions by means of a fastening section 402 (for example, a peripherally arranged and / or surrounding the central region). When the diaphragm 408 is subjected to a mechanical load, it redirects the load to the mounting portion 402 to which it is fixed against shear stress. The membrane 408 may be supported by the second substrate 302.The formation of micromechanical structure 106 may include, in 400 c: forming a cantilever 410 (e.g., a cantilever beam) which includes or is formed from first substrate subsection 102 aor at least first subregion 104 a. The cantilever 410 may be configured to be deflected (at a distance from the second substrate 302) in a first end region 410 e(also referred to as a functional region) of the freely suspended portion 404 while the second (opposite) end region 420 eof the freely suspended portion 404 (at or near the second substrate 302) is held (e.g. immovable) by means of the fastening portion 402. The end region 410 eof the freely suspended portion 404 can be separated, e.g. deflectable, from the second substrate 302 by means of a gap (opposite the circumferential region).The cantilever 410 can be understood as an elongated structural element, such as an elongated plate or a beam, which is anchored to a second end region 420 e(for example opposite the first end region) by means of a fastening section 402. In other words, the cantilever 410 can have a protruding first end region 410 ewhich is mounted on one side. When the cantilever 410 is subjected to a mechanical load, it redirects the load onto the fastening section 402, to which it is fixed against a shear stress. The cantilever 410 may be supported by the second substrate 302.Forming the micromechanical structure 106 may include, in 400 a, in 400 band / or in 400 c: forming an additional layer 412 (also referred to as base layer 412) over the first substrate portion 102 a(e.g. over the first portion 402 and / or over the second portion 404), e.g. by means of PVD or CVD. The base layer 412 and the first substrate portion 102 amay be different from each other, e.g. in their semiconductor material and / or in their crystallization type. For example, the base layer 412 may be polycrystalline and / or include or be formed from Si.For example, after severing the substrate 102 and optional planarization and structuring of the first substrate section 102 a(e.g. comprising or formed from an SiC layer), a deposition of poly-Si (polycrystalline silicon) can take place, which further serves as a functional membrane 408 or cantilever 410. For example, the first substrate portion 102 a(e.g., comprising or formed from SiC) may provide a supporting / stabilizing structure (also referred to as a stiffening structure) to increase the robustness of the poly-Si membrane. Optionally, the first substrate portion 102 amay be patterned.In general, micromechanical structure 106 may include a functional structure 544, e.g., membrane 408 and / or cantilever 410. The functional structure 544 may include the anchored portion 402 and the flared portion 404, which may be (e.g. monolithically) monocrystalline and / or may be formed by processing the monocrystalline substrate piece 102 a.FIGS. 5A, 5B, 5C and 5D each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 500 a: providing the second substrate 302 including an electrode 502. The electrode 502 (also referred to as first electrode 502) may be formed before the first substrate 102 and the second substrate 302 are secured together (also referred to as pre-processing the second substrate 302).The first electrode 502 may have, for example, a thickness (vertical extension) of less than about 2 μm, e.g. less than about 1 μm, e.g. greater than or equal to about 600 nm, e.g. when the first electrode 502 comprises or is formed from a polycrystalline material (e.g. polysilicon or nitride).If the first electrode 502 is formed from a substrate portion (as described below), e.g. of single-crystalline material (e.g. SiC), the first electrode 502 may be formed thinner, e.g. have a thickness (vertical extension) of less than about 600 nm, e.g. less than about 300 nm, e.g. less than or equal to about 150 nm, e.g. greater than or equal to about 100 nm.Forming the micromechanical structure 106 may include, in 500 b: forming an additional electrode 512 (also referred to as second electrode 512) including or formed from the first substrate subsection 102 aor at least the first subregion 104 a. For example, the second electrode 512 may have a smaller thickness (vertical extension) than the first electrode 502 (e.g., if the second electrode 512 comprises more single crystal material than the first electrode 502).In general, the micromechanical structure 106 may include an electronic component 502, 512 (also referred to as microelectromechanical structure 106), e.g., the first electrode 502 and / or the second electrode 512. Analogous to the functional structure 544, the electronic (active) structural element 502, 512 may include an anchored portion 402 and the protruding portion 404, which may (e.g. monolithically) be monocrystalline and / or may be formed by processing the monocrystalline substrate piece 102 a. The electronic structural element 502, 512 may have a greater stiffness than the functional structure 544. The stiffness can be understood as the resistance of a structure to elastic deformation by a force or a torque (bending moment or torsion moment, depending on the stress). The electronic (active) structural element 502, 512 may transmit an electrical signal during operation of the micromechanical structure 106.Forming the second electrode 512 may include forming a cavity 302 h(also referred to as first cavity 302 h) between the substrate portion 102 aand the first electrode 502, e.g., by removing a material (e.g., a sacrificial material) between the substrate portion 102 aand the first electrode 502.The forming of the cavity 302 hmay be performed, for example, after the arranging of the first substrate portion 102 aand / or the forming of the first electrode 502. For example, a sacrificial layer may be arranged between the first electrode 502 and the first substrate portion 102 a, which sacrificial layer is removed for forming the cavity 302 h, e.g. by means of etching out / releasing the sacrificial layer. Alternatively or additionally, the sacrificial layer can serve for exact adjustment of the vertical distances between membrane and electrode(s).Alternatively, the cavity 302 hmay be formed before the first substrate portion 102 ais arranged over the first electrode 502, i.e. illustratively floating (over the cavity 302 h).The second electrode 512 may have, for example, a thickness (vertical extension) smaller than the first electrode 502 and / or of less than 600 nm, e.g. less than or equal to about 300 nm, e.g. less than or equal to about 150 nm, e.g. in a range from about 100 nm to about 400 nm. For example, the second electrode 512 may be formed thinner than the first electrode 502 (which may have a thickness in a range from about 610 nm to about 2000 nm, for example) using the single crystalline material (e.g., SiC).The first substrate section 102 aor its first partial region 104 acan spatially span the cavity 302 h.Forming the micromechanical structure 106 may include, in 500 c: forming a functional structure 544 (e.g. providing a membrane 408 or a cantilever 410) including the first substrate portion 102 aor at least the first portion 104 a. Forming the functional structure 544 may include forming a first cavity 302 hbetween the substrate portion 102 aand the first electrode. The functional structure 544 may include a functional region deflectable relative to the second substrate 302 (e.g., into the first cavity 302 h) in response to a force applied thereto. The first substrate section 102 aor its first partial region 104 acan spatially span the first cavity 302 h.Forming the micromechanical structure 106 may include, in 500 d: forming the second electrode 512, wherein the functional structure 544 is arranged between the second electrode 512 and the first electrode 502. The functional structure 544 may have the first substrate portion 102 aor at least the first portion 104 aor be formed therefrom (or at least from a part thereof). Forming the functional structure 544 may include: forming a first cavity 302 hbetween the substrate portion 102 aand the first electrode 502 and / or forming a second cavity 312 hbetween the substrate portion 102 aand the second electrode 512.Forming the second cavity 312 hmay be performed, for example, after arranging the first substrate portion 102 aand / or forming the first electrode 502 and / or the second electrode 512. For example, a sacrificial layer may be arranged between the second electrode 512 and the first substrate portion 102 a, which sacrificial layer is removed for forming the second cavity 312 h, e.g. by means of exposing / etching out the sacrificial layer. Alternatively or additionally, the sacrificial layer can serve for exact adjustment of the vertical distances between membrane and electrode(s).Alternatively, the second cavity 312 hmay be formed before the second electrode 512 is arranged over the first substrate portion 102 a, i.e. illustratively floating (over the second cavity 312 h).Alternatively, the substrate portion 102 amay be used to form the second electrode 512.The first substrate section 102 aor its first partial region 104 acan spatially span the first cavity 302 hand / or the second cavity 312 h.The substrate section 102 aarranged between the two electrodes 502, 512can provide the membrane 408 or the cantilever 410, for example. Optionally, a second substrate portion 102 bmay be used to form the second electrode 512, as described in more detail below.FIGS. 6A, 6B and 6C each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Providing the substrate 102 may include, in 600 a: structuring the first substrate portion 102 a(and optionally the adhesion layer 304), e.g. after forming the target separation layer 202. For example, the patterning of the first substrate portion 102 amay include exposing at least one or more regions of the target separation layer 202. Alternatively or additionally, the structuring of the first substrate section 102 acan comprise forming one or more openings in the substrate section 102 a, which openings penetrate the substrate section 102 a, for example.The structuring of the first substrate portion 102 acan be effected by means of etching, for example by means of wet chemical etching, dry etching (for example plasma etching or sputter etching) and / or by means of ion etching. Alternatively or additionally, the structuring of the first substrate section 102 acan be effected by means of a mask (e.g. the mask formed by means of a photolithography process). The photolithography process may include, for example: applying a hard mask (e.g., including or formed from photoresist) over the first substrate portion 102 a; and patterning the first substrate portion 102 aby etching the first substrate portion 102 a. Alternatively, a maskless patterning process may be used, e.g., a laser patterning process (e.g., a CNC laser process, i.e., a computer assisted numerically controlled laser process).Forming the micromechanical structure 106 may include, in 600 b: forming a stiffening structure 602 (e.g. including struts, strips or rings) including or formed from the (e.g. structured) first substrate subsection 102 aor at least the first subregion 104 a. The stiffening structure 602 may be arranged over a deflectable region (e.g. the freely suspended portion), e.g. over a membrane 408 or a cantilever 410. For example, the second substrate 302 may have a functional structure 544 before being bonded to the first substrate 102. Alternatively, the deflectable region may be deposited on or above the stiffening structure 602, e.g. comprising or formed from polycrystalline silicon (also referred to as poly-Si).According to various embodiments, the deflectable region may be arranged between the stiffening structure 602 and the cavity 302 h. Alternatively or additionally, the or an additional stiffening structure 602 may be arranged between the cavity 302 hand the deflectable region, e.g. adjacent to the cavity 302 h.Alternatively, the deflectable region (e.g. a membrane 408 or a cantilever 410) may include or be formed from the single-crystal semiconductor material and the stiffening structure 602 may include or be formed from a polycrystalline semiconductor material, e.g. poly-Si. For example, the stiffening structure 602 may be deposited on or above the deflectable region, e.g. comprising or formed from polycrystalline silicon (also referred to as poly-Si).The stiffening structure 602 may have a greater mechanical hardness, a greater stiffness, or a greater modulus of elasticity than the functional structure 544. By means of the structuring of the first substrate section 102 a, the stiffness of the stiffening structure 602 can be varied. The structuring of the first substrate section 102 acan take place before or after the arrangement above the deflectable structure 408, 410.Forming the micromechanical structure 106 may include, in 600 c: forming a stiffening structure 602, which includes or is formed from the (e.g. structured) first substrate subsection 102 aor at least the first partial region 104 a, between the first electrode 502 and the second electrode 512. The stiffening structure 602 may be arranged above a functional structure, e.g. above a membrane 408 or a cantilever 410.FIGS. 7A and 7B illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Providing the substrate 102 may include, in 700 a: forming the target separation layer 202 by ion implantation 204 through the first substrate portion 102 aand through the adhesion layer 304. Alternatively or additionally, the method in 700 acan comprise: changing a chemical composition of the first substrate portion 102 aby means of ion implantation 204, e.g. the second ion implantation 204. Before this, the first ion implantation 204 may optionally be performed (e.g. to form the separation layer 202). Alternatively or additionally, the first ion implantation 204 and the second ion implantation 204 may differ, e.g. in at least the implanted material and / or the implantation depth of the implantation energy.Optionally, in 700 a, the method may include: patterning the first substrate portion 102 a. The mechanical properties of a stiffening structure formed later, if appropriate, therefrom can thus be adapted.The (e.g. hydrophilic) adhesion layer 304 can comprise or be formed from, for example, a (e.g. hydrophilic) dielectric, e.g. an oxide (also referred to as oxide layer 304), e.g. a semiconductor oxide.For example, the substrate 102 may be a single crystal silicon carbide (SiC) substrate 102 or may include at least one SiC single crystal region 104.For example, the target separation layer 202 may be formed by implanting 204 hydrogen ions (e.g., using hydrogen gas-H 2).Attaching the first substrate 102 (also referred to as carrier substrate) to the second substrate 302 may include, in 700 b: bonding 702 the substrate 102 to the additional substrate 302. The additional substrate 302 may be provided (e.g., pre-processed, also referred to as pre-processing) to include a first electrode 502. The first electrode 502 may be provided in preconfigured form, for example.The second substrate 302 may include, for example, an electrode layer 704 including the first electrode 502. The electrode layer 704 may comprise an adhesion material (e.g. hydrophilic), e.g. a dielectric (e.g. a hydrophilic) (e.g. an oxide), in which the first electrode 502 is embedded. The first electrode 502 may include multiple layers, of which a first layer 502 amay include or be formed from a nitride, a second layer 502 bmay include or be formed from a semiconductor material (e.g., Si or SiC), a third layer 502 cmay include or be formed from a nitride, and a fourth layer 502 dmay include or be formed from multiple protrusions, e.g., including or formed from a semiconductor material (e.g., Si, e.g., poly-Si). Optionally, the first electrode may include a plurality of openings (ventilation openings) that penetrate through the plurality of layers of the first electrode 502.The second substrate 302 (also referred to as target substrate) may have a substrate body 706, above which the first electrode 502 or the electrode layer 704 is arranged. An insulation layer 302 p, for example comprising or formed from an oxide, can optionally be arranged between the substrate body 706 and the first electrode 502 or the electrode layer 704. The substrate body 706 may include or be formed from one or the semiconductor material, e.g. Si.For example, an SiC carrier substrate 102 may be provided in 700 awith a surface oxide layer 304 and subsequently be brought into contact with an already pre-processed target substrate 302 in 700 b. The bonding of the two substrates 102, 302 to one another can be effected by means of a bonding process, for example by means of a molecular (hydrophilic) bonding process (i.e. molecular adhesion optionally reinforced by a thermal treatment).Optionally, the first electrode 502 (e.g. the second layer 502 b) may comprise or be formed from (or at least from a part of) a single-crystal substrate portion, as will be described in more detail below (compare 1200 b).FIGS. 8A and 8B each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).The severing of the first substrate 102 can comprise, in 800 a: thermally processing the first substrate 102, for example by supplying thermal energy to the first substrate 102. The thermal processing may include: heating the first substrate 102, e.g. to at least a temperature up to which the target separating layer 202 is temperature-stable and / or to at least approximately 700° C., e.g. to at least approximately 900° C. By means of the thermal processing of the first substrate 102, a structural change of the first substrate 102 may be brought about, e.g. in the target separating layer 202. The structural change can cause the connection of the two substrate sections 102 a, 102 bto be canceled from one another.For example, in 800 a, by means of a thermal treatment of the composite system comprising the first substrate 102 and the second substrate 302 (e.g. approximately 1 hour at approximately 500-900° C.), the layer stack 102 a, 304 (e.g. SiO 2- SiC) can be separated from the SiC carrier substrate 102 according to the predefined desired separation layer 202 (also referred to as gap zone 202). The SiC carrier substrate can then be reused (e.g. recycled) and serve for forming further sensors at wafer level, as will be described in more detail below.The severing of the first substrate 102 may comprise, in 800 b: removing the second substrate portion 102 bfrom the first substrate portion 102 a. For example, the first substrate section 102 acan be at least partially exposed in 800 b.Optionally, after the severing in 800 b, the first substrate section 102 acan be altered, e.g. a chemical or structural alteration of the first substrate section 102 a, e.g. a structuring or alteration of the chemical composition of the first substrate section 102 a. The chemical composition of the first substrate section 102 acan be changed, for example, by means of the second ion implantation 204. Before this, the first ion implantation 204 may optionally be performed (e.g. to form the separation layer 202). Alternatively or additionally, the first ion implantation 204 and the second ion implantation 204 may differ, e.g. in at least the implanted material and / or the implantation depth of the implantation energy.The structuring can be effected, for example, by means of a lithography process and / or by means of a plasma etching. The patterning may include, for example: applying a hard mask (e.g., including or formed from photoresist) over the first substrate portion 102 a; and patterning the first substrate portion 102 aby etching the first substrate portion 102 a. Alternatively, a maskless patterning process may be used, e.g., a laser patterning process (e.g., a CNC laser process, i.e., a computer assisted numerically controlled laser process).By changing the chemical composition of the first substrate section 102 a, an elastic modulus and / or a mechanical hardness of the first substrate section 102 acan be changed, e.g. the elastic modulus is reduced and / or the mechanical hardness is reduced. By means of the structuring of the first substrate section 102 a, a mechanical stiffness of the first substrate section 102 acan be changed, e.g. reduced.The (illustratively defined-cleaved) monocrystalline layer 102 a(e.g. an SiC layer 102 a) remains connected to the target substrate 304 by means of the insulator layer 304 (e.g. comprising an oxide or formed therefrom) and can later provide a membrane of a sensor, for example. An optional change of the monocrystalline layer 102 a(and thus of the membrane properties) can take place in 800 b, for example by means of an implantation of nitrogen (N 2). If, on account of the severing (splitting), the monocrystalline layer 102 a(e.g. SiC layer 102 a) has a roughness greater than a predetermined value, smoothing (planarization) can be carried out before the deposition of further layers on the monocrystalline layer 102 a, e.g. by means of a chemical mechanical processing (also referred to as a CMP process).FIGS. 9A and 9B each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 900 a: electrically contacting the first electrode 502 and / or the first substrate section 102 a. For example, the first electrode 502 and / or the first substrate section 102 acan be connected to an electrical contact pad 902, e.g. by means of electrical lines (e.g. comprising vias) which comprise a metal or can be formed therefrom. The electrical contact pads may be provided, for example, by means of a metallization 902. Metallization 902 may be electrically coupled (i.e., electrically conductively connected) to first electrode 502, substrate body 706, and / or first substrate subsection 102 a, for example, by means of vias. The metallization 902 and / or the electrical lines may be electrically conductive, i.e., have an electrical conductivity of more than about 10 6 Siemens / meter. The metallization 902 and / or the electrical lines may include or be formed from a metal, for example a corrosion-resistant metal (e.g. noble metal) such as molybdenum, tungsten and / or gold or also another metal such as copper and / or aluminum. Alternatively or additionally, metallization 902 may include or be formed from a nitride (e.g., tantalum nitride) (may also be corrosion resistant).Forming the micromechanical structure 106 may optionally include, in 900 a: forming one or more layers over the first substrate subsection 102 a, of which at least one first layer 904 may include or be formed from a dielectric (e.g. an oxide) and / or of which at least one second layer 902 (e.g. a metallization 902) may include or be formed from a metal, and of which optionally at least one third layer 906 may include or be formed from a passivation material (also referred to as a passivation layer 906). The passivation layer 906 may include, for example, a plurality of openings (also referred to as contact openings), each opening exposing a contact pad of the metallization 902. The contact openings may be formed, for example, by means of an etching process and / or by means of a lithography process. The passivation material may be electrically insulating, i.e. have an electrical conductivity in a range of less than about 10 -6 Siemens / meter. For example, the passivation material may be an oxide (e.g., a semiconductor oxide), polymer (e.g., a resin or varnish), or nitride (e.g., a semiconductor nitride).Forming the micromechanical structure 106 may optionally include, in 900 a: forming an opening 906 o(first opening 906 o) over the first substrate portion 102 a, e.g. in the passivation layer 906.Forming the micromechanical structure 106 may include, in 900 b: thinning the additional substrate 302 and / or forming an opening 706 o(second opening 706 o) in the additional substrate 302. Thinning and / or forming the second opening 706 omay be performed from a side of the additional substrate 302 opposite the first substrate portion 102 a. The opening 706 omay extend through the substrate body 706, for example. Forming the opening 706 oin the additional substrate 302 may stop at the insulation layer 302 p, for example. For example, the isolation layer 302 pmay be used as an etch stop.FIG. 10 illustrates a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 1000: exposing (e.g. mechanically releasing) the first electrode 502 and / or the first substrate section 102 a(at least in the second portion 404), e.g. respectively on mutually opposite sides. The exposing may be accomplished by enlarging the first opening 906o and / or by enlarging the second opening 706o. By means of the exposing, a cavity 302 h(i.e. a portion of the second opening 706 o) may be formed between the first electrode 502 and the first substrate portion 102 a. The vertical extension of the cavity 302 hmay be defined by the thickness of the electrode layer 704.The first substrate section 102 a(e.g. its second portion 404) may be coupled to the additional substrate 302 by means of the suspension portion 402. Alternatively or additionally, the first substrate section 102 a(e.g. its second section 404) can be electrically contacted by means of the suspension section 402.The free-hanging portion 404 may be exposed by means of the first opening 906 oand / or by means of the second opening 706 oand / or separate them from one another.Micromechanical structure 106 illustrated in FIG. 10 (e.g., a capacitive sensor) may be provided, for example, in a single-electrode configuration (also referred to as a single-counter-electrode configuration, e.g., the membrane may be understood as an electrode to counter-electrode). The single electrode configuration may include a functional region 404 deflectable relative to the additional substrate 302 (e.g., into the first cavity 302 h) in response to a force applied thereto, and exactly one first electrode 502. The first electrode 502 and the functional region 404 may be capacitively coupled to each other. The first electrode 502 may be arranged between the functional region 404 and the substrate body 706 (also referred to as bottom single electrode configuration or bottom single counter electrode configuration). The first substrate section 102 acan provide the membrane 408 or the cantilever 410, for example.FIGS. 11A and 11B each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).The provision of the first substrate 102 may be configured in 1100 a, as in 700 a.Attaching the first substrate 102 to the second substrate 302 may be configured in 1100 bsuch as in 700 b, except that the electrode of the second substrate 302 is omitted. The second substrate 302 may include an additional (e.g. hydrophilic) adhesion layer 1104 in 1100 b, which may include or be formed from the adhesion material and / or is in physical contact with the substrate body 706. The (e.g. dielectric) adhesion material may include or be formed from an oxide and / or a dielectric, e.g. a semiconductor oxide, e.g. silicon oxide.FIGS. 12A and 12B each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).The severing of the first substrate 102 can be configured in 1200 a, as in 800 a(only that the second substrate 302 does not have an electrode). The optional modification of the first substrate section 102 acan be configured in 1200 b, as in 800 b.According to various embodiments, in 1200 b, a first electrode 502 may be formed, which (e.g. the second layer 502 bthereof) comprises or is formed from the first substrate portion 102 a(also referred to as pre-processing of the second substrate 302). In this case, the method can proceed to method step 800 a.Alternatively, it may be provided to form a functional structure 544 which comprises or is formed from the first substrate portion 102 a. In this case, the method can proceed to method step 1300 a.FIGS. 13A and 13B illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 1300 a: forming the second electrode 512 over the first substrate portion 102 a.The second electrode 512 may include multiple layers, of which a first layer 512 amay include or be formed from a nitride, a second layer 512 bmay include or be formed from a semiconductor material (e.g., Si, e.g., poly-Si), a third layer 512 cmay include or be formed from a nitride, and a fourth layer may include or be formed from multiple protrusions, e.g., including or being formed from a semiconductor material (e.g., Si, e.g., poly-Si). Optionally, the second electrode 512 may include a plurality of openings (ventilation openings) penetrating through the plurality of layers of the second electrode 512.Forming the micromechanical structure 106 may further include, in 1300 a: electrically contacting the second electrode 512 and / or the first substrate portion 102 a. For example, the second electrode 512 and / or the first substrate section 102 amay be connected to an electrical contact pad 902, e.g. by means of electrical lines (e.g. vias) which may comprise or be formed from a metal. The electrical contact pads may be provided, for example, by means of a metallization 902. Metallization 902 may be electrically coupled (i.e., electrically conductively connected) to second electrode 512, substrate body 706, and / or first substrate subsection 102 a, for example, by means of vias. The metallization 902 and / or the electrical lines may be electrically conductive, i.e., have an electrical conductivity of more than about 10 6 Siemens / meter. The metallization 902 and / or the electrical lines may include or be formed from a metal, for example a corrosion-resistant metal (e.g. noble metal) such as molybdenum, tungsten and / or gold or also another metal such as copper and / or aluminum. Alternatively or additionally, metallization 902 may include or be formed from a nitride (e.g., tantalum nitride) (may also be corrosion resistant).Forming the micromechanical structure 106 may optionally include, in 1300 a: forming one or more layers over the first substrate portion 102 a, of which at least one layer 904 may include or be formed from an oxide and / or of which at least one layer 902 may include or be formed from a metallization 902, and of which optionally at least one layer 906 may include or be formed from a passivation material. The passivation layer 906 may include, for example, a plurality of openings, each opening exposing a contact pad of the metallization 902. The passivation material may be electrically insulating, i.e., have an electrical conductivity of less than about 10 -6 Siemens / meter. For example, the passivation material may be an oxide (e.g., a semiconductor oxide), polymer (e.g., a resin or varnish), or nitride (e.g., a semiconductor nitride).Forming the micromechanical structure 106 may optionally include, in 1300 a: forming a first opening 906 oover the first substrate portion 102 aand / or over the second electrode, e.g. in the passivation layer 906.Forming the second electrode 512 may optionally include, in 1300 a: forming the second electrode 512 (e.g. its second layer 512 b) including or formed from a second single crystal substrate portion 102 b. For example, the second monocrystalline substrate subsection 102 bmay be provided by means of severing the substrate residue.Forming the micromechanical structure 106 may include, in 1300 b: thinning the additional substrate 302 and / or forming a second opening 706 oin the additional substrate 302. Thinning and / or forming the second opening 706 omay be performed from a side of the additional substrate 302 opposite the first substrate portion 102 a. The opening 706 omay extend through the substrate body 706, for example. Forming the opening 706 oin the additional substrate 302 may stop at the additional adhesion layer 1104, for example. For example, the additional adhesion layer 1104 may be used as an etch stop.FIG. 14 illustrates a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 1400: exposing (e.g., mechanically releasing) the second electrode 512 and / or the first substrate portion 102 a. The exposing may be accomplished by enlarging the first opening 906 oand / or by enlarging the second opening 706 o, e.g., on opposite sides, respectively. By means of the exposing, a cavity 312 h(i.e. a portion of the first opening 906 o) may be formed between the second electrode 512 and the first substrate portion 102 a.The first substrate section 102 amay be coupled to the additional substrate 302 by means of the suspension portion 402. Alternatively or additionally, the first substrate section 102 acan be electrically contacted by means of the suspension section 402.The free-hanging portion 404 may be exposed by means of the first opening 906 oand / or by means of the second opening 706 oand / or separate them from one another.Micromechanical structure 106 illustrated in FIG. 14 (e.g., a capacitive sensor) may be provided, for example, in a single-electrode configuration (also referred to as a single-counter-electrode configuration). The single electrode configuration may include a functional region 404 deflectable relative to the additional substrate 302 in response to a force applied thereto, and exactly one second electrode 512. The second electrode 512 and the functional region 404 may be capacitively coupled to each other. The functional region 404 may be arranged between the second electrode 512 and the substrate body 706 (also referred to as top-single-electrode configuration or top-single-counter-electrode configuration).The substrate section 102 aarranged between the second electrode 512 and the substrate body 706 can provide the membrane 408 or the cantilever 410, for example. Alternatively, the first substrate portion 102 amay be used to form the second electrode 512. For example, the second layer 512 bof the second electrode 512 may include or be formed from (or at least from a part of) the first substrate portion 102 a.Optionally, a second substrate portion 102 bmay be used to form the second electrode 512. For example, the second layer 512 bof the second electrode 512 may include or be formed from (or at least from a part of) the second substrate portion 102 b.FIGS. 15A and 15B each illustrate a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 1500 a: providing the first substrate portion 102 aand / or the second substrate 302, e.g. configured as in 800 aand / or in 800 b.Forming the micromechanical structure 106 may include, in 1500 a: forming the second electrode 512 over the first substrate portion 102 a, e.g., configured as 1300 a.Forming the micromechanical structure 106 may include, in 1500 b: thinning the additional substrate 302 and / or forming an opening 706 o(second opening 706 o) in the additional substrate 302. Thinning and / or forming the second opening 706 omay be performed from a side of the additional substrate 302 opposite the first substrate portion 102 a. The opening 706 omay extend through the substrate body 706, for example. Forming the opening 706 oin the additional substrate 302 may stop at the insulation layer 302 p, for example. For example, the isolation layer 302 pmay be used as an etch stop.The metallization 902 (e.g. comprising contact pads) may be electrically coupled (i.e. electrically conductively connected) to the first electrode 502, the second electrode 512, the substrate body 706 and / or the first substrate subsection 102 a, for example, by means of vias. The metallization 902 and / or the electrical lines may be electrically conductive, i.e., have an electrical conductivity of more than about 10 6 Siemens / meter. The metallization 902 and / or the electrical lines may include or be formed from a metal, e.g. copper and / or aluminum.FIG. 16 illustrates a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).Forming the micromechanical structure 106 may include, in 1600: exposing (e.g. mechanically releasing) the first electrode 502, the second electrode 512 and / or the first substrate portion 102 a. The exposing may be accomplished by enlarging the first opening 906 oand / or by enlarging the second opening 706 o, e.g., on opposite sides, respectively. By means of the exposing, a first cavity 302 h(i.e. a portion of the second opening 706 o) may be formed between the first electrode 502 and the first substrate portion 102 a. By means of the exposing, a second cavity 312 h(i.e. a portion of the first opening 906 o) may be formed between the second electrode 512 and the first substrate portion 102 a.The first substrate section 102 amay be coupled to the additional substrate 302 by means of the suspension portion 402. Alternatively or additionally, the first substrate section 102 acan be electrically contacted by means of the suspension section 402.The free-hanging portion 404 may be exposed by means of the first opening 906 oand / or by means of the second opening 706 oand / or separate them from one another.Micromechanical structure 106 illustrated in FIG. 16 (e.g., a capacitive sensor) may be provided, for example, in a dual-electrode configuration (also referred to as a dual-counter-electrode configuration). The dual electrode configuration may include a functional region 404 deflectable relative to the additional substrate 302 in response to a force applied thereto, and exactly two electrodes 502, 512 between which the functional region 404 is disposed. The first electrode 502, the second electrode 512 and the functional region 404 may be capacitively coupled to each other.The substrate section 102 aarranged between the two electrodes 502, 512can provide the membrane 408 or the cantilever 410, for example. Optionally, a second substrate portion 102 bmay be used to form the first electrode 502 or the second electrode 512. Alternatively, the substrate portion 102 amay be used to form the first electrode 502 or the second electrode 512.According to various embodiments, a dual electrode configuration may be provided in which at least one electrode 502, 512 and / or the functional region 404 may comprise or be formed from a single crystal material, e.g. single crystal GaN, single crystal SiC and / or single crystal Si.The dual electrode configuration may provide a sensor (e.g., a microphone), for example. Compared to the single electrode configuration, the dual electrode configuration may have a greater SNR and / or a lower THD. The production of the dual electrode configuration can be carried out, for example, analogously to that of the upper side single electrode configuration and differ from the fact that the target substrate 302 is or is preprocessed.FIG. 17 illustrates a method according to various embodiments in a schematic side view or cross-sectional view (e.g. viewed along a main processing side 102 o).The method may include, in 1700 a: separating a first single-crystalline layer 102 afrom a substrate 102 by separating the substrate 102 in a single-crystalline region (leaving a substrate residue 102 rof the substrate 102).The method may include, in 1700 b: forming a first micromechanical structure 106 including the first single-crystal layer 102 a. The first single-crystal layer 102 amay provide the functional structure 544, the stiffening structure 602, the first electrode 502 or the second electrode 512 of the first micromechanical structure 106, for example.The method may optionally include, in 1700 c: providing a substrate 102 including or formed from the substrate residue 102 r. The providing may optionally include: thermally processing the substrate residue 102 r, e.g. by annealing it (for annealing the crystal structure).The method may optionally include, in 1701 a: separating a second single-crystalline layer 102 bfrom the substrate 102 (i.e. from the substrate residue 102 rused as substrate 102) by severing the substrate 102 in a single-crystalline region, wherein a substrate residue 102 rremains from the substrate 102.The method may optionally include, in 1700 b, forming a second micromechanical structure 116 including the second single-crystal layer 102 b. The second single-crystal layer 102 bmay provide the functional structure 544, the stiffening structure 602, the first electrode 502 or the second electrode 512 of the second micromechanical structure 116, for example.Alternatively, in 1700 d, the second single crystal layer 102 bmay be added to the first micromechanical structure 106. The second single-crystal layer 102 bmay provide the functional region, the stiffening structure 602 or the second electrode 512 of the second micromechanical structure 116, for example. For example, the first single-crystal layer 102 amay provide the functional structure 544 of the first micromechanical structure 106 and the second single-crystal layer 102 bmay provide an electrode 502, 512 of the first micromechanical structure 106.The provision of monocrystalline layers 102 a, 102 bby means of severing the remaining substrate residue 102 rmay be effected (also referred to as re-using the substrate) until the monocrystalline substrate 102 is used up. Thus, the single crystal substrate 102 can be utilized more effectively, which reduces costs.According to various embodiments, the severing can be effected by means of a smartcut process. Smartcut can be understood as a technological process which enables the transfer of layers of single-crystal semiconductor material to a technical carrier (i.e. the second substrate) (also referred to as transfer).For example, a silicon-on-insulator substrate or a silicon carbide-on-insulator substrate may be provided, which includes the second substrate 302 and the single-crystal layer 102 a, 102 b.

Claims

Method for processing a single-crystalline substrate (102), wherein the method comprises: • severing (100b) the substrate (102) along a main processing side into at least two single-crystalline substrate segments (102a, 102b), wherein the substrate (102) comprises a target separating layer (202), by means of which the at least two substrate segments (102a, 102b) are connected to one another, and wherein the severing (100b) is effected by releasing a cohesion of the target separating layer (202); • fastening (300a) at least one single-crystalline substrate segment of the at least two substrate segments (102a, 102b) to an additional substrate (302) before the severing (100b); • forming (100c) a micromechanical structure (106), which comprises the at least one monocrystalline substrate portion of the at least two substrate portions (102a, 102b); and • changing a mechanical characteristic and / or electrical characteristic of the at least one monocrystalline substrate portion by means of ion implantation, wherein the changing takes place before the severing (100b).The method of claim 1, further comprising: forming (200a, 200c) the target separation layer (202) by an additional ion implantation.The method of claim 1, further comprising: forming (200a, 200c) the target separation layer (202) by changing a chemical composition between the two substrate portions (102a, 102b).Method according to claim 3, wherein by means of the modification of the chemical composition a resistance of the substrate (102) between the two substrate sections (102a, 102b) to the severing (100b) is reduced.The method of claim 1, wherein the attaching (300a) comprises bonding the substrate (102) and the additional substrate (302) together.Method according to one of Claims 1 to 5, wherein the fastening (300a) is effected by means of an adhesion layer (304) which is arranged between the at least one monocrystalline substrate section and the additional substrate (302).The method of any one of claims 1 to 6, wherein the additional substrate (302) comprises an electrode (502); or wherein the electrode (502) is formed by the at least one single crystalline substrate section.The method according to any of claims 1 to 7, wherein forming (100c) the micromechanical structure (106) comprises forming an additional electrode (512), and wherein the at least one single-crystal substrate portion is arranged between the additional electrode (512) and the additional substrate (302); or wherein the additional electrode (512) is formed by means of the at least one single-crystal substrate portion.Method according to one of Claims 1 to 8, wherein the formation (100c) of the micromechanical structure (106) comprises forming a membrane (408) or a cantilever (410) which(s) comprises the at least one monocrystalline substrate portion.The method according to any one of claims 1 to 9, wherein the altering of the mechanical characteristic and / or the electrical characteristic of the at least one single-crystalline substrate portion by means of ion implantation comprises altering the mechanical characteristic.The method according to any one of claims 1 to 9, wherein the altering of the mechanical characteristic and / or the electrical characteristic of the at least one single-crystalline substrate part by means of ion implantation comprises altering the electrical characteristic.The method according to any one of claims 1 to 11, wherein the target separation layer (202) has a greater impurity density than the at least one single-crystal substrate portion, and / or wherein the target separation layer (202) has a greater porosity than the at least one single-crystal substrate portion.Method according to one of Claims 1 to 12, • wherein the at least two substrate segments (102a, 102b) have three substrate segments; and wherein the micromechanical structure (106) has two substrate segments (102a, 102b) of the three substrate segments, and / or wherein the method furthermore has: • forming (100c) an additional micromechanical structure (116) which has another substrate segment of the three substrate segments.Method, comprising: • forming (200a, 200c) a target separating layer (202) in a single-crystalline substrate (102); • fastening (300a) the substrate (102) to an additional substrate (302); wherein a substrate section (102a) of the substrate (102) is arranged between the target separating layer (202) and the additional substrate (302); • severing (100b) the substrate (102) in the target separating layer (202); • forming (100c) a micromechanical structure (106), which comprises at least the substrate section (102a); and • changing a mechanical characteristic and / or electrical characteristic of the substrate section by means of ion implantation, wherein the changing takes place before the severing (100b).The method of claim 14, wherein altering the mechanical characteristic and / or the electrical characteristic of the substrate portion using ion implantation comprises altering the mechanical characteristic.The method of claim 14, wherein altering the mechanical characteristic and / or the electrical characteristic of the substrate portion using ion implantation comprises altering the electrical characteristic.

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