Method and device for producing at least one modification in a solid

Abstract

Method for producing modifications (1) inside a solid body (2), comprising the steps: Providing the solid body (2), wherein the solid body (2) has a first surface (4) and a second surface (6) spaced from the first surface (4) in a vertical direction (z), wherein a thickness of the solid body (2) is a function of a lateral position (x, y) along the first surface (4) and / or along the second surface (6); Exposing a volume portion (8) of the solid body (2) to light waves (10) of different wavelengths via the first surface (4), wherein the light waves are partially reflected at the first surface (4) and partially coupled into the solid body (2) and reflected at the second surface (6); At least partially detecting light parameters of the reflected light waves (11) with a sensor device (12) and determining distance information from at least part of the detected light parameters; Determining a thickness of the solid body (2) in the volume fraction (8) of the solid body (2) from the distance information; Introducing laser radiation (14) into the volume portion (8) of the solid body (2) via the first surface (4) to produce modifications (1) in the interior of the solid body (2), wherein at least one laser parameter of the laser radiation (14) is adjusted at least as a function of the thickness of the volume portion (8) such that the modifications (1) have a predefined distance from the second surface (6), the modifications are produced within a detachment plane, and wherein the detachment plane is aligned parallel to or at an angle of at most 4° to the second surface (6).

Description

The publication EP 2 729 099 B1 describes an eye surgical treatment system. Before the actual ablative laser irradiation of the cornea in order to reduce the defective vision, a preceding flat femto laser cut partially releases an upper, thin corneal lamella (flap). For this purpose, the femto laser beam falls through the front side of the cornea, focused at a depth of, for example, 150 μm, and dissolves the tissue there. The lamella thus formed remains firmly connected to the corneal body on one side, is folded away from the eye center and, after ablative laser irradiation, is folded back again to the original position. An imaging method allows adjustment of the hinge axis of the blade to the patient's astigmatism axis.The subject matter described below lies in the technical field of semiconductor processing, in particular in the field of ingot or wafer or Boule processing. The document WO 2017 / 060 251 A1 describes a method and an apparatus for vertically slicing wafers. A confocal chromatic measurement device determines the surface contour and / or a map of the thickness of the wafer. A laser treatment step produces so-called "filaments" in different height sections of the wafer by locally modifying the wafer material. The surface contour or the thickness model of the wafer is used for fine adjustment of the filaments. Along the filaments, the wafer is cut vertically. The confocal measurement determines, for example, the position of scattering centers, wherein the scattering centers can be filaments produced beforehand. The starting point of a second filament is determined as a function of the position of a previously produced first filament. Another type of processing represents, for example, a reduction in the thickness of the solid body treated, in particular a separation of the solid body into a plurality of portions, in particular solid body layers, which are physically separated from one another.Possible methods for reducing the thickness of a solid body are, for example, polishing or lapping. By these methods, material is removed from the solid body by machining. Machining can lead on the one hand to the loss of high-quality solid material and on the other hand to the wear of the tool, which can lead to high costs.Another possible method for separating a solid layer from a solid is a sawing method. In this case, a saw blade or saw wire is brought into contact with the solid body. The sawing tool then works cutting through the solid body. The cut material components are considered to be loss. Further, the saw is subject to high wear, thereby resulting in high cost.SummaryOne aspect relates to methods for creating modifications inside a solid according to claims 1 and 5.Another aspect of the present disclosure relates to an apparatus according to claim 15.Further aspects of the disclosure relate to a computer program product and a programmable circuit.Brief Description of the FiguresFurther embodiments, goals and / or properties are explained on the basis of the following description, the subclaims and on the basis of the accompanying drawings, in which exemplary embodiments for methods described here and devices described here are sometimes shown by way of example. Components which can be used in exemplary embodiments of the method and / or which correspond at least substantially with respect to their function in the figures can be identified here by the same reference numerals, wherein these components do not have to be numbered or explained in all figures. The elements, structures and / or components shown in the drawings are not necessarily shown true to scale with respect to one another.The drawings illustrate only exemplary embodiments and together with the description serve to explain the same. It is to be understood that other embodiments also exist and structural or logical changes may be made without departing from the scope defined by the claims. The description of the exemplary embodiments is not limiting in this respect. In particular, elements of exemplary embodiments described below can be combined with elements of other of the described exemplary embodiments, provided that something else does not explicitly result from the context.The figures show: FIG. 1 schematically shows an arrangement according to an exemplary embodiment by means of which modifications can be produced in solid bodies, and FIG. 2 schematically shows measured values, as can be output, for example, by the sensor device shown in FIG. 1.Detailed DescriptionOne aspect of the present disclosure relates to a method of creating modifications within a solid. This method comprises, for example, providing a solid body. The solid body can be a solid-state crystal, in particular a semiconductor crystal, or the solid body can have a solid-state crystal. For example, the solid body comprises a wafer (e.g. a growth substrate) or is a wafer. Alternatively or additionally, the solid body can comprise or be a mold and / or ingot. The solid body may comprise further components, such as epitaxially grown layers, metallizations and / or passivation layers, and / or such components may be applied to the solid body.The solid body has a first surface and a second surface spaced apart from the first surface in a vertical direction. The solid body may extend along lateral directions. Perpendicular to the lateral directions, in the vertical direction, the solid body has the thickness that is small compared to the (e.g. at most 30% or at most 10%) extension of the solid body in the lateral directions. For example, the first and / or the second surface enclose an angle of at most 10° with a plane spanned by the lateral directions. A lateral position may correspond to a point on a plane spanned by the lateral directions. The lateral position can be specified, for example, in Cartesian coordinates and / or in polar coordinates.At least one parameter of the solid body is a function of a lateral position along the first surface and / or along the second surface. In particular, the parameter can vary along the lateral position. The parameter of the solid is at least one of thickness and transmission. A crystal parameter may be, for example, at least one of: orientation of the crystal structure and / or of the crystal of the solid body, polytype variation in the crystal lattice of the solid body, stress states in the solid body, in particular in the crystal of the solid body, dislocations (e.g. screw dislocations), defects in the solid body.It is possible that a thickness of the solid body is a function of a lateral position along the first surface and / or along the second surface. In some exemplary embodiments, the thickness of the solid body may vary along the lateral position, for example on account of surface irregularities and / or on account of surfaces running non-plane-parallel. The variation can be effected, for example, according to a so-called total thickness variation (TTV). For example, the TTV is at most 10 μm or at most 7 μm and / or at least 1 μm or at least 3 μm. The solid body can be wedge-shaped, for example. The first and / or the second surface can / can also be a non-freely accessible interface within a composite structure. This is the case, for example, when the first and / or the second surface is / are provided with a further component (e.g. a further layer) and / or with component structures.Alternatively or additionally, a transmittance of the solid body can be a function of a lateral position along the first surface and / or along the second surface. It is possible that the transmittance of the solid body varies along the lateral directions. For example, a dopant concentration of the solid body varies along the lateral directions. The solid body can thus have a different transmittance at a lateral position than at a different lateral position.It is also additionally possible that a crystal parameter is a function of a lateral position along the first surface and / or along the second surface. For example, the solid body includes local variations of crystal orientation and / or dislocations and / or polytype variations along the lateral position.The method comprises applying light waves of different wavelengths to a first volume portion of the solid body. The light waves may have at least two (or at least four or at least ten) different wavelengths. It is possible for the light waves to have a maximum of ten or a maximum of twenty or a maximum of fifty or a maximum of one hundred or a maximum of two hundred different wavelengths. For example, the light waves are or comprise polychromatic light. The exposure can be effected continuously or in time-spaced light pulses.For example, light waves of different wavelengths can be spatially and / or temporally separated from one another during the application of the light. It is possible for the light waves to be spatially spectrally fanned out and / or focused to different extents according to their wavelength. Different wavelength components of the light waves can then have different axial focal widths and / or different focal positions. Typically, at least two focuses of the light waves are located in the solid body when acted upon. In particular, a focus closest to the light source ("innermost focus") and a focus furthest from the light source ("outermost focus") may exist. The distance between the position of the innermost focus and the position of the outermost focus is also referred to below as "fan-out" (fan-out). The fanning out can correspond to the measurement range of a sensor assembly or be correlated therewith.The fanning out can correspond approximately (i.e. with an accuracy of e.g. ±20% of the fanning out) to the averaged thickness of the solid body (for example at least 200 μm or at least 300 μm and at most 500 μm or at most 400 μm) or even be greater than the averaged thickness of the solid body (e.g. at least 500 μm). A greater fanning out can enable a comprehensive measurement of the solid body. The fanning out can, however, also be smaller than the averaged optical thickness of the solid body (for example at least 50 μm or at least 100 μm and at most 200 μm or at most 150 μm). A smaller fanning out can enable, for example, a more accurate position determination of a plane (e.g. a detachment plane) within the solid body. The fanning out may be dependent on the refractive index of the medium through which the light waves propagate. The aforementioned values for the fanning out can apply to the propagation in air and / or in the solid body.The light waves are introduced into the volume portion via the first surface and / or the first surface is impinged upon by the light waves. The light waves are partially reflected at the first surface. The light waves are partially coupled into the solid body and reflected at the second surface.The volume portion extends, for example, between a first surface portion of the first surface, via which the light waves are introduced into the solid body and / or at which at least a part of the light waves is reflected, and a second surface portion of the second surface, at which at least a part of the light waves is reflected. The surface portion of the first surface may have a different lateral extent than the surface portion of the second surface. For example, at least the first surface portion has a lateral extent of at least 1 μm and at most 40 μm, for example at most 20 μm. The volume proportion can be determined, for example, by a size of a light cone of the light waves in the solid body. In other words: the light waves can illuminate a region of the solid body between the first and the second surface, wherein at least a part of the region or the entire region corresponds to the volume proportion. The volume portion can extend obliquely to the vertical direction or along the vertical direction. The surface portion of the first surface and the surface portion of the second surface may at least partially overlap in a vertical projection.At least partial (e.g. a majority or complete) detection of light parameters of the reflected light waves takes place. The light parameters can be at least one of the following parameters or can comprise one of the following parameters: wavelength, intensity, wavelength-dependent intensity, polarization, wavelength-dependent polarization, time-dependent intensity. The light parameters are detected with a sensor device, in particular by means of a sensor of the sensor device. For this purpose, the light waves can be detected by the sensor device and the light parameters can be determined from the detected light waves. The sensor device can output the detected light parameters in the form of signals and / or data. At least distance information or intensity information is determined from the detected light parameters and location information and / or polarization information can additionally be determined. However, it is also possible to ascertain further information, such as, for example, defect information (information about dislocations and / or defects) and / or stress information (information about stress states) and / or color information (information about the color of defects and / or modifications in the solid body). From the ascertained information, for example, averaged parameters of the solid body in the volume proportion can be determined. The ascertainment can be carried out by means of an evaluation unit. For example, the evaluation unit comprises a programmable circuit and / or a computer for this purpose and / or is part of a computer.The sensor device can contain at least one confocal chromatic sensor. A confocal chromatic sensor uses chromatic aberration for distance determination in particular. For example, the sensor device contains at least one or exactly one of the following sensor components or a combination of at least two of these sensor components: CCD sensor (also called CCD chip), photodiode (e.g. one- or two-dimensional photodiode array), microchannel plate (e.g. nitrogen-cooled microchannel plate), active pixel sensor (e.g. two-dimensional active pixel sensor and / or CMOS sensor). The sensor device can be configured to detect at least a part of the light waves reflected on the first surface and at least a part of the light waves reflected on the second surface. In particular, different spectral components of the light waves reflected on the two surfaces are determined with the sensor device. The detection can be performed in a time-resolved and / or spectral-resolved and / or polarization-resolved and / or spatially resolved manner.According to a first alternative, distance information is determined from at least a part of the detected light parameters. The distance information may include, for example, information on the distance between the sensor device and the first surface and between the sensor device and the second surface in the volume portion. Alternatively or additionally, the distance information may contain information about the distance between the first surface and the second surface in the volume portion. From the distance information, the thickness of the solid in the volume portion is determined. In this case, the concept is sometimes followed that different spectral components of the light waves propagate in different ways in the solid body and / or have different focuses in the solid body. A distance of the sensor device from the first surface and / or from the second surface in the volume portion can then be determined, for example, on the basis of a chromatic-confocal distance measurement. The distance of the sensor device from the two surfaces can be the distance information or the distance information can be correlated to the distance (for example, it can be directly dependent on the distance).In one exemplary embodiment, the determination of a thickness, in particular an average thickness or an average square thickness, of the solid body in the volume proportion of the solid body can be effected from the information, in particular from the distance information. In exemplary embodiments of the method, the thickness can be determined for a plurality of volume fractions, in particular for the entire solid body.According to a second alternative, intensity information is determined from the detected light parameters. For example, the intensity information comprises spectrally resolved intensities of the first reflected light waves and / or of the second reflected light waves.The method then includes determining a transmittance of the solid in the volume portion of the solid from the intensity information. For example, for this purpose, the intensity information is evaluated for at least one, in particular for at least two, wavelength(s) of the reflected light waves. In addition, distance information can be used for determining the transmittance.In a next step, laser radiation is introduced into the volume portion of the solid body via the first surface in order to generate at least one modification in the interior of the solid body. At least one laser parameter of the laser radiation is set as a function of the thickness and / or the transmittance of the volume fraction in such a way that the at least one modification has a predefined distance from the second surface. The laser radiation can thus be configured to generate the modifications depending on the determined distance between the second surface and the first surface in the volume portion.In some exemplary embodiments, the at least one laser parameter, in particular a plurality of laser parameters, is set as a function of the thickness and the transmittance of the volume fraction. This allows precise positioning of the modification, in particular of a detachment plane.In general, in addition to the thickness and / or the transmittance, other parameters of the solid body in the volume proportion can also be determined on the basis of the light parameters detected by means of the sensor device. These parameters of the solid body can likewise be used to set the laser parameters and / or information can be determined from these parameters, on the basis of which information the laser parameter is set. It is thus possible, for example, to determine the orientation of the crystal structure of the solid body (e.g. a rotation by / or a tilt) relative to the laser radiation (e.g. relative to the polarization and / or to the Hunting vector of the laser radiation). In particular in the case of anisotropic and / or birefringent solid bodies (such as e.g. hexagonal SiC, in particular 4H-SiC), the formation of the modification can be dependent on the orientation of the crystal planes in the solid body relative to the spatial orientation (e.g. relative to the Hunting vector) of the laser radiation and / or on the polarization of the laser radiation. The orientation can be determined, for example, from at least two comparative measurements of the light parameters, in which at least one measurement parameter (e.g. the tilt and / or rotation of the solid body relative to the sensor device and / or the polarization of the light waves) is varied.In some embodiments, the at least one modification is generated in particular within the same plane (e.g. a detachment plane), wherein this plane is aligned in particular parallel or approximately parallel (i.e. with an angle of at most 4° or at most 2° or at most 1°) to the second surface. It is possible that several modifications, in particular more than 10 or more than 100 or more than 1000 modifications, are produced in the solid body to produce a detachment plane.After the introduction of a plurality of modifications, in particular in the form of a detachment plane, a method described here can involve a separation of a solid-state layer from the solid-state body. In particular, the solid body can be split into at least two parts. For example, a portion of the split solid having device structures has a thickness less than that of the portion of the split solid having no device structures. The part of the split solid body which does not have any component structures can be provided with component structures in further method steps. For example, a renewed separation of a solid layer can subsequently take place.For example, by means of a method described here, it is possible to define the distance between the second surface and the at least one modification, in particular the distance between the second surface and the detachment plane, very precisely, such that the distance corresponds to the predefined distance. This can be effected in particular by surface irregularities of the first surface and / or thickness fluctuations along the lateral directions having no or only minor or negligible effects on the location of the position generation.Alternatively or additionally, the transmittance of the solid body can be determined as a function of position by means of a method described here. By determining the transmittance for a volume fraction, the laser radiation, in particular its intensity and / or focus, can be adjusted in a targeted manner for the volume fraction. Thus, for example, the effects of a varying transmittance, in particular varying dopings and / or dopant concentrations, on the modification generation can be limited or at least compensated. A possible variation of a crystal parameter, which can lead to different transmissions along the solid body, can also be compensated for thereby.According to some embodiments, a portion of the light waves is reflected at the first surface (first reflected light waves) and another portion of the light waves is reflected at the second surface (second reflected light waves). The term "reflected light waves" in the following denotes the first reflected light waves and / or (in particular "and") the second reflected light waves. A portion of the light parameters of the two reflected parts of the light waves can be detected in each case by the sensor device and then evaluated, for example by an evaluation unit. Before detection with the sensor device for detecting the light parameters, the two reflected parts of the light waves can be at least partially superimposed. For example, a superposition different from a coherent superposition is provided here, in particular if no interferometric measuring principle is present. Alternatively, a spatial and / or temporal separation can also be provided. The first and second reflected light waves may have different wavelength components and / or the wavelength components of the first and second reflected light waves may run differently in time and / or space. In some exemplary embodiments, the first reflected light waves and the second reflected light waves can be detected separately from one another by means of the sensor device, in particular using the same sensor device.The solid body can be transparent to the light waves of the different wavelengths. The solid body can be irradiated with other light waves, wherein the light waves can have a wavelength at which the solid body is not transparent. The solid is considered to be transparent to the light waves of a wavelength if the transmittance for this wavelength is at least 60%, in particular at least 70%, or at least 80%, or at least 90%. For example, the different wavelengths are in the visible range of the electromagnetic spectrum (between 380 nm and 780 nm). Alternatively or additionally, the wavelengths can be in the near infrared (between 780 nm and 3 μm, in particular between 900 nm and 1200 nm).According to at least one embodiment, the set laser parameter of the laser radiation can comprise or be at least one of the following parameters: focus position (i.e. focus) of the laser radiation, focus size (i.e. focus width) of the laser radiation, intensity and / or energy of the laser radiation, wavelength (in particular peak wavelength) of the laser radiation, intensity distribution in a laser pulse of the laser radiation, pulse duration of a laser pulse of the laser radiation, polarization of the laser radiation, repetition rate of the laser radiation. In particular, the laser parameter can comprise the focus position and the intensity of the laser radiation. It is possible that the location of the modification can be adjusted in a targeted manner via the laser parameters mentioned, in particular via the focus position and the intensity. The setting of the laser parameters can take place for each laser pulse with which one or more modifications are generated and / or for each volume proportion in which the at least one modification is generated.The laser radiation can have pulsed portions and / or continuous portions. Typically, the laser radiation is pulsed. The focus position and / or the focus variable can be adjusted, for example, by means of an optical system. The laser parameters may depend partly on one another-for example the wavelength of the laser parameter and the intensity may correlate.In some exemplary embodiments, the detected light parameters comprise polarizations or polarization changes of the reflected light waves detected by the sensor device. Polarization information of the volume portion can be determined from the polarizations. In particular, it is possible for the polarization of the reflected light waves to be detected in a spatially resolved manner. Alternatively or additionally, polarization information can be provided, for example, in the form of data, wherein the polarization information describes the polarization of the reflected radiation and / or of the laser radiation.It is possible that the at least one laser parameter for generating the modification in the volume portion is set depending on the polarization information of the volume portion. Typically, the polarization of the laser radiation is adjusted as a function of the polarization information. For example, the at least one laser parameter is set exclusively as a function of the polarization information or additionally as a function of other information.For example, the polarization information and / or the polarization can be used to draw conclusions about at least one crystal parameter of the solid, in particular about at least one of the following parameters: orientation of the crystal structure and / or of the crystal of the solid, polytype variation in the crystal lattice of the solid, stress states in the solid, in particular in the crystal of the solid, dislocations (e.g. screw dislocations), defects in the solid.Stress states in the solid body, in particular in the crystal framework of the solid body, can influence, for example, the formation and / or the propagation of cracks in the material of the solid body. Accordingly, it may be necessary to adapt at least one laser parameter for generating the modifications in a region of higher stress compared to a region of lower stress. Alternatively or additionally, the crack formation and / or the crack propagation can be influenced by the orientation of the crystal relative to the at least one generated modification. The orientation of the modification to that of the crystal may sometimes depend on the polytype of the crystal lattice. Dislocations can likewise have an influence on the crack formation and / or the crack propagation. In particular, a birefringence of the material of the solid body in the volume proportion can be compensated for by a corresponding setting of the laser parameter or the laser parameters.For the determination of the crystal parameter from the polarization, the sensor device can be configured linearly polarized in some embodiments. In particular, only one polarization defined relative to the sensor device is then measured. By measuring at least twice under different directions of incidence of the light waves and / or under different sensor rotations, conclusions can be drawn about the crystal parameter. Alternatively or additionally, the light waves can be linearly polarized at least partially, in particular completely; in this case, it is possible to rotate the polarization of the light waves. An at least two measurement then yields an image about the crystal parameter.According to one specific embodiment, the light parameters to be detected may include intensities of the reflected light waves, which are detected in particular by means of the sensor device. Intensity information can be determined for and / or from the intensities, wherein the at least one laser parameter is set as a function of the intensity information. It is possible that the thickness of the solid body in the volume portion is determined at least partially from the intensity information. Alternatively or additionally, it is possible that a transmittance of the solid body in the volume portion is determined from the intensity information and the at least one laser parameter is set as a function of the transmittance. For example, the intensity information contains the intensities for at least two wavelength components of the reflected light waves (in particular the first and the second reflected light waves). For example, distances within the solid body can generally be determined from the intensity information. In addition to the thickness of the volume portion, alternatively or additionally the position of a predambigration and / or of an inclusion and / or of an already generated modification can be determined. Furthermore, an absorption in the volume proportion can be determined from the intensity values (e.g. by means of a difference formation). For example, a laser parameter (for example the energy and / or the focus position) required for the volume portion can additionally be determined therefrom.According to a further embodiment, the sensor device detects the reflected light waves, e.g. for detecting the light parameters for determining the intensity signals, at the same volume portion at least or exactly twice. The reflected light waves can be detected and / or detected at least twice (in particular each time) for different lengths. Alternatively or additionally, further measurement parameters can be changed (e.g. the polarization of the light waves and / or of the reflected light waves, the distance of the sensor device from the first surface and / or the fanning out of the light waves). The light parameters can be determined by the sensor device as a function of the detected light waves. It is also possible here for more than two signals (e.g. more than two intensity signals), in particular more than two signals per wavelength, to be evaluated per volume fraction. For example, the intensity information representing the light waves detected for different lengths is adjusted. For example, the distance information can be determined very precisely by the different detection times (detection times).The light waves can be emitted by a radiation source, in particular continuously. The radiation source can be arranged on one side of the solid body, in particular on and / or above the first surface. A detection time of the sensor device can be adjustable. The detection time is the time duration during which the reflected light waves are detected and / or detected. The detection time of the sensor device can differ for different wavelengths. For example, the sensor device can be adjustable and / or set in such a way that the reflected light waves are detected at the same location, in particular for the same volume fraction, at least for two measurements for different detection times. Alternatively or additionally, the light waves can be applied to the volume portion for different lengths of time (in time). Thus, for example, a volume proportion could first be exposed to light waves for a first detection time t 1 and then exposed to light waves for a second detection time t 2, wherein the first and the second detection time can differ. For example, the following applies: t1*1.1<t2or t1*1.3<t2or t1*1.5<t2or t1*1.8<t2or t1*2<t2or vice versa, i.e.: t2*1.1<t1or t2*1.3<t1or t2*1.5<t1or t2*1.8<t1or t2*2<t1.In some exemplary embodiments, both distance information (e.g. for determining the thickness) and intensity information (e.g. for determining the transmittance) are determined. The determination of the thickness and the determination of the intensity information of the light waves (in particular for the determination of the transmittance) can be effected for the same proportion of the solid, in particular within a time window of less than 2 seconds or less than 1 second or less than 0.5 second or simultaneously. For example, it is thereby possible to measure the respective volume proportion within a short time. This can be helpful for generating a plurality of maps, in particular an energy map and a thickness map. The term "map" describes a property of the solid body in a spatially resolved manner, for example.In general, it is possible for the thickness and / or the transmittance and / or the polarization to be determined in each case for a plurality of volume fractions. This applies, mutatismutatally, to further parameters of the solid body which can be determined by means of the light waves. In particular, the thickness and / or the transmittance can be determined for so many volume fractions that a thickness variation and / or a variation of the transmittance along the entire solid body can be determined. The different volume portions may partially overlap laterally. That is, a lateral extent of the light waves at the first surface (corresponds to the lateral extent of the first surface portion) is greater than a center-to-center distance of adjacent volume portions. The different volume fractions have, for example, essentially the same volume (mm 3) by volume or to the extent of at least 80% or to the extent of at least 90% or to the extent of at least 95%. Alternatively or additionally, the different volume portions may not laterally overlap; in this case, adjacent volume portions may directly adjoin or be spaced apart from each other. A lateral extent of the light waves at the first surface is in this case less than or equal to a center-to-center distance of adjacent volume portions.In some exemplary embodiments, a center-to-center distance of adjacent volume fractions may be at least 150 μm (or at least 250 μm, or at least 400 μm, or at least 800 μm, or at least 1.5 mm). This may be the case for both overlapping and spaced-apart volume portions. Regardless of whether the volume portions overlap or adjoin one another or are arranged at a distance from one another, the determined parameters can be interpolated between the volume portions. In particular in the case of spaced volume portions, such interpolation may be required in some embodiments to enable the adjustment of the laser parameters for the generation of modifications in a region between the volume portions.For example, for the measurement of different volume fractions, the light waves and the solid body are moved relative to one another, wherein the thickness and / or the transmittance of a volume fraction illuminated by the light waves is determined between two successive movements. It is possible that the thickness and / or the transmittance is first determined for a volume fraction and the at least one modification is subsequently generated in this volume fraction. Alternatively, the respective thickness and / or the respective transmittance can be determined first for a plurality of volume fractions, e.g. for all volume fractions, and the at least one modification can then be generated in each of the plurality of volume fractions.According to a further embodiment, the method further comprises the following steps: applying, at least after the generation of the modification in the volume proportion, the volume proportion of the solid body with the light waves of different wavelengths and / or with further light waves of different wavelengths via the first surface. The light waves and / or the further light waves are partially reflected at the first surface and partially coupled into the solid body and reflected at the at least one modification. Furthermore, light parameters of the reflected light waves and / or of the reflected further light waves are at least partially detected by a sensor device and / or a further sensor device.The further sensor device can be designed like the sensor device. Alternatively, the further sensor device can have a different optical system than the sensor device. The further light waves can be formed like the light waves. Alternatively, the further light waves can differ from the light waves in at least one of the following properties: distance of the light source for generating the further light waves from the first surface and / or from the second surface; position of the focuses of the different wavelength components in the solid body; fanning out of the light waves; polarization of the light waves.Location information can be determined from at least some of the light parameters detected with the sensor device and / or the further sensor device. From the location information, a distance between the at least one modification and the first surface and / or between the at least one modification and the second surface in the volume proportion of the solid body can be determined. As a result, for example, the position of one or more modifications in the interior of the solid body can be checked. The location information can be the same as the distance information and / or be determined analogously to the distance information. The disclosure previously for the distance information thus applies, mutatismutatally, to the location information and vice versa.Alternatively or additionally, color information can be determined from initially a part of the light parameters detected with the sensor device and / or the further sensor device. A quality of the modification can be determined from the color information. The color information can correspond to a gloss image of the at least one modification, in particular of the detachment plane. The glossy image can have different color components. It may be possible to determine from the color of the glossy image whether the energy and / or the intensity of the laser radiation has been selected correctly. Furthermore, it can be checked whether a sufficient number of modifications have been introduced into the solid body. The latter can alternatively or additionally also be determined from the location information. The aforementioned information can be stored as reference data and reused for setting the laser parameters when modifications are generated in a subsequent solid body. Alternatively or additionally, the same solid body can be treated again with the laser radiation, wherein the energy and / or the intensity and / or the focus position of the laser radiation can be adjusted according to the information from the gloss image during the repeated treatment. For example, this makes it possible to correct modifications introduced with too low an energy and / or intensity and / or additionally introduce modifications in the case of an insufficient number of modifications.For the determination of the color information, it may be necessary to measure the at least one modification in a first measurement using the light waves. In a subsequent second measurement, the at least one modification can be measured with further light waves that differ from the light waves. The further light waves differ from the light waves in particular in their fanning out and / or in the focus position of the same wavelengths. It is possible that the further light waves are generated with the same light source as the light waves. The fanning out can then be changed, for example, by adapting an optics of the light source. Alternatively or additionally, the focus position can be varied by displacing the light source relative to the solid body. However, it is also possible for the further light waves to be generated with a further light source which is different from the light source.According to a further embodiment, the sensor device and a radiation source by means of which the light waves are generated are arranged at a distance closer to the first surface than to the second surface. If a plurality of sensor devices and / or a plurality of radiation sources by means of which the light waves are generated are provided, then these can be arranged closer to the first surface than to the second surface. The second surface can have, for example, components such as a layer (e.g. a metallic coating or a passivation), an immersion liquid and / or component structures, which is why better coupling of the light waves can take place via the first surface.In relation to the solid body, in particular the concrete solid body, according to a further embodiment, the distance information and / or the intensity information and / or the thickness and / or the transmittance and / or the light parameters are stored as reference data on a data carrier at least as a function of the lateral position and / or the volume proportion along the first surface and / or the second surface. In alternative or additional exemplary embodiments, it is possible for information other than the aforementioned information to be stored as reference data (e.g. location information, polarization information, crystal parameters, gloss image, and / or color information). The lateral position and / or the volume portion can be stored in the form of location coordinates (e.g. Cartesian coordinates or polar coordinates) and / or in the form of a surface portion of the first surface and / or in a manner identifiable in another way (e.g. numbering of surface portions and / or volume portions). 3D location coordinates and / or volume fractions and / or other identification data for the location can also be stored.According to a further embodiment, modifications are generated in a solid and reference data for this are provided and / or output and / or stored and modifications are subsequently generated in a further solid or on a further plane in the solid, wherein the at least one laser parameter of the laser radiation for generating the modifications in the further solid or on the further plane is additionally set at least depending on at least a part of the stored or provided or output reference data. The reference data relating to the solid body or first solid body treated beforehand, in particular directly beforehand, can be stored in particular. The configuration of the laser radiation can be effected during a treatment of a solid body as a function of a combination of information (e.g. a combination of data and / or signals), wherein a part of the information is the information determined during a treatment of the solid body (e.g. by means of the sensor device and / or the evaluation unit) and a part of the information is the stored data relating to one or more partially or completely treated solid bodies. Completely treated here is to be understood in such a way that the generation of modification for generating a detachment plane in the solid body is concluded. However, further modifications may be produced at a different level in the same solid.According to one embodiment, the solid body comprises or consists of silicon carbide (SiC), in particular 4H-SiC. The fact that a solid body consists of a material is generally to be understood in such a way that the solid body can have, in addition to the material from which it consists, impurities and / or dopants caused by production. For example, the solid body comprises more than 80% (mass) or more than 99% (mass) of SiC. A solid body can be understood to mean only the portion between the first surface and the second surface, provided it consists of the same material. In other words: additional components (e.g. coatings, passivations, component structures, etc.) may be present, which differ from the material of the solid body. In particular, the solid body can be part of a composite structure. In other embodiments, the solid body may include or consist of at least one of the following materials: gallium nitride (GaN), silicon (Si), sapphire (Al 2 O 3), gallium III oxide (Ga 2 O 3), gallium arsenide (GaAs).According to one embodiment, the solid body has component structures of a semiconductor component on the second surface. The component structures can be formed at least partially opaque and / or at least partially reflective to the light waves of the different wavelengths. Alternatively or additionally, the solid body can have at least one layer, such as a metallization, that is opaque and / or reflective for the light waves on the second surface. The modification generation can take place in particular with component structures already applied. The solid-state portion remaining on the applied component structures and / or the layer (e.g. in the form of a further solid-state layer) can be very thin in this case, since an adequate strength can be achieved by the applied component structures and / or the layer. For example, the total material yield can be increased as a result and / or grinding of the solid-state portion can be reduced.According to a further embodiment, a use of a method according to one of the aforementioned subject matters for separating a solid-state layer from the solid state and / or for producing a semiconductor component is provided. The semiconductor component may comprise at least one of the aforementioned component structures. The semiconductor component is, for example, an electrical semiconductor component, in particular for switching currents. The semiconductor component contains, in particular, a pn junction. For example, the semiconductor component may be a diode (e.g. a Schottky diode), a field effect transistor (e.g. a MOSFET) and / or an IGBT.According to a further embodiment, a device is provided. The device can be configured and / or provided in particular for carrying out an aforementioned method. That is, all features disclosed in connection with the method can also be disclosed for the device and vice versa.The apparatus can have at least one holding device for defined alignment of the solid body. Furthermore, the device has a radiation source (e.g. a broadband radiation source, a white light source) for generating light waves of different wavelengths in a predefined spectrum. The radiation source can be, for example, a broadband radiation source which emits polychromatic light in the visible and / or infrared range of the electromagnetic spectrum. Exemplary components that may be used as or in a radiation source include at least one of: a white light source, a light emitting diode (e.g., an emitting light emitting diode or a laser diode with a wavelength conversion phosphor), a non-linear fiber, a halogen lamp, a xenon lamp. The apparatus also has a sensor device for detecting light parameters of at least some of the light waves. For the detection of the light parameters, the sensor device can be configured for detecting light waves for determining the light parameters.Furthermore, the device can have an evaluation unit for ascertaining at least one of the following items of information from the light parameters: distance information, intensity information, location information, polarization information, color information. The evaluation unit can have a computing unit. For example, the evaluation unit contains a programmable circuit and / or is a computing unit. The evaluation unit can contain parts of a computer. In addition or as an alternative to the evaluation unit, a computing unit can be provided.The apparatus has a laser device for generating laser radiation for generating modifications in the interior of the solid body. The apparatus also comprises a drive unit for driving the laser device as a function of the information determined by the sensor device. The laser device is configured to change at least one laser parameter of the laser radiation depending on the information determined by the sensor device.According to a further embodiment, the radiation source and the sensor device form a sensor assembly (also called "first sensor assembly" in some exemplary embodiments). The sensor assembly may be disposed in a fixed relative position to the laser device. In this way, it may be possible, for example, to align the individual components of the assembly precisely with respect to one another. For example, the assembly is surrounded in sections by a housing. For example, the assembly can thereby be protected from damage and dirt. Further, the entire assembly may be interchangeable.According to a further embodiment, at least one second sensor assembly is provided. The second sensor assembly likewise comprises a radiation source and a sensor device. The first sensor assembly, the second sensor assembly and a component of the optics of the laser device, by means of which the laser radiation is focused into the solid body, can be arranged along a straight line. It is possible for the component of the optics of the laser device to be arranged between the sensor assemblies. By means of a device resulting from this, a precise measurement of the solid body and thus a precise generation of modifications can be made possible. Furthermore, this device can enable the position of the modifications generated to be checked. Thus, a very rapid and precise machining can be carried out with, in particular, continuously carried out checking.The programmable circuit may comprise a field programmable gate array (FPGA), for example, or may be an FPGA. The circuit has an input, an output and a processing unit. The input is configured to receive sensor signals from the sensor device. For example, the sensor device can have an output for this purpose, which is coupled to the input of the circuit.The processing unit is configured to ascertain information from the sensor signals of the sensor device. In particular, the programmable circuit can be programmed in such a way that the processing unit can ascertain information from the sensor signals of the sensor device. The ascertained information can be, for example, signals and / or data. The determined information includes at least one of distance information, intensity information, location information, polarization information, color information. In addition, the ascertained information can contain control signals for controlling a control unit of a laser device and / or control signals for controlling the control unit of a laser device can be ascertained from at least some of the ascertained information. In addition, the information may include laser parameters to be provided by a laser device.The output is configured to output information determined by the circuit. For example, the ascertained information is output to a further component within the circuit, for example to a further processing unit. Alternatively or additionally, the ascertained information can be passed on in the form of output signals to a further component outside the circuit. At least some of the ascertained information can be output, for example, to a drive unit of a laser device. For example, the output of the circuit is coupled to an input of the drive unit for this purpose.The programmable circuit is provided and / or configured to determine a transmittance and / or a thickness and / or a crystal parameter in a volume proportion of a solid body. The programmable circuit can be configured such that sensor signals originating from a sensor device can be evaluated by means of the programmable circuit. The sensor signals can describe and / or comprise light parameters of light waves detected by means of the sensor device.In some exemplary embodiments, the programmable circuit (in particular the processing unit) can be real-time capable. "real-time capable" means in this context that the data rate of the programmable circuit (i.e. the rate at which the programmable circuit ascertains the information from the sensor signals and outputs it via the output) corresponds at least to the data rate at which the information is made available at the input. For example, the clock rate of the programmable circuit (in particular of the processing unit) is at least 50 kHz, in particular at least 1 MHz. The data rate at which the information is provided at the input can depend on the one hand on the data rate at which the light parameters are measured and on the other hand on the number of pixels of the sensor device. In the case of a plurality of sensors in the sensor device, the total number of pixels must be taken into account. By means of a programmable circuit, it may be possible to process a very large amount of information in a very short time, in particular in real time.A computer program product is provided as a further embodiment, wherein the computer program product comprises instructions. The commands can be provided and / or configured for programming a programmable circuit described here. Alternatively or additionally, the commands for controlling a device for executing a method described here may be provided and / or configured. In particular, the instructions may cause a device described herein or an alternative device to perform a method described herein.On the basis of the schematic arrangement shown in FIG. 1, exemplary embodiments of a method described here and of a device described here are explained in more detail.The arrangement shown in FIG. 1 contains, purely by way of example, a solid body 2, a sensor assembly 22, a laser device 13 and a holding device 341 for holding the solid body 2. the sensor assembly 22, the laser device 13, the radiation source 9 and the holding device 341 can be part of an apparatus for carrying out a method for producing at least one modification 1 in the interior of a solid body.The solid body 2 has a first surface 4 and a second surface 6 spaced apart from the first surface 4 in a vertical direction z. A distance between the first surface 4 and the second surface 6 corresponds to a thickness of the solid body 2. the thickness of the solid body 2 is a function of a lateral position x,yalong the first surface 4 and / or along the second surface 6. However, other variations of the thickness of the solid body 2 along the lateral position x, y are also conceivable. For example, the (in particular two-dimensional) function of the thickness along the lateral position x, y corresponds to a wave-like function, a straight line, a quadratic function or an irregular function. Alternatively, the thickness of the solid body along the lateral position x,y may be constant-the function of the thickness is then a constant.Alternative or additional embodiments of the solid body 2 are conceivable, in which the solid body has a transmission(s) varying along the lateral position x, y and / or crystal parameters. Other parameters of the solid body 2 can also vary along the lateral position x, y.The holding device 341 may include a carrier device 34 and a connecting layer 32. For example, the bonding layer 32 includes a potting compound, an adhesive, and / or a foam. The connecting layer 32 can be configured to mechanically connect the carrier device 34 and the solid body 2 to one another, in particular via a mechanically and / or chemically non-destructively releasable connection. The carrier device 34 can be designed as a temporary carrier which is removed from the solid body 2 again, for example, in subsequent process steps and / or can be used for mechanically holding a new solid body 2. The carrier device 34 can be designed to be mechanically stabilizing for the solid body 2, in particular a part of the solid body 2 to be separated. For example, the carrier device 34 is a glass carrier, a film or a chuck or comprises one of the mentioned. In particular in the case of a film, the bonding layer 32 is optional.On a side of the solid body 2 facing the holding device 341 and / or on the second surface 6, the solid body 2 can have component structures 16. Furthermore, one or more metallization(s) 161 may be provided, which may / may serve for the electrical contacting of the component structures 16. The component structures 16 can be formed on the second surface 6 of the solid body 2. The component structures 16 and / or the metallization 161 may be at least partially embedded in the connection layer 32 and / or directly adjoin the connection layer 32.The sensor assembly 22 of the apparatus can have at least one radiation source 9 and a sensor device 12. As an alternative to the exemplary embodiment shown, the sensor device 12 and the radiation source 9 can also be constructed structurally separately from one another and / or spaced apart from one another and / or independently of one another. The radiation source 9 can be configured to emit light waves 10 of different wavelengths in a predefined electromagnetic spectrum. For example, the radiation source 9 is a white light source and / or emits broadband light. The sensor device 12 can be configured to record light parameters of at least a part of the light waves 10, 11 emitted by the radiation source 9 and possibly reflected, in particular to detect the light waves 10, 11.The laser device 13 may include, for example, a laser source. The laser device 13 can be configured to generate laser radiation 14, in particular in the near infrared. The laser device 13 can have an optics (e.g. a lens, an objective, a telescope, a deflection mirror and / or a diffractive optical element), by means of which the laser radiation can be directed and / or focused into the interior of the solid body 2. At least one laser parameter of the laser radiation 14 is adjustable. The at least one laser parameter can be set, for example, by means of at least one of the optics and / or by changing parameters of the laser source of the laser device 13 (e.g. in the case of the pulse duration or the wavelength).Optionally, a second sensor assembly 24 can be provided, wherein the second sensor assembly 24 can likewise have a radiation source 9 and a sensor device 12. Alternatively, a second radiation source and a second sensor device can be provided separately from one another. The radiation source 9 and / or the sensor device 12 of the second sensor assembly 24 can be designed like the radiation source 9 and / or the sensor device 12 of the (first) sensor assembly 22 or respectively differ from the radiation source and / or the sensor device 12 of the (first) sensor assembly 22 or both differ. It is possible that the first sensor assembly 22, the second sensor assembly 24 and a component of the optics of the laser device 13, by means of which the laser radiation 14 is directed and / or focused into the solid body 2, are arranged in a straight line. The component of the optics of the laser device 13 can be arranged between the two sensor assemblies 22, 24.The component of the optics can be, for example, a lens or a deflection mirror and / or a diffractive optical element. However, other of the aforementioned optics are also conceivable. However, the device can also be designed without a second sensor assembly 24.In a method for producing a modification 1 in the solid body 2, light waves 10 of different wavelengths can be introduced into a volume portion 8 of the solid body 2. The volume portion 8 can correspond to the part of the solid body 2 illuminated by the light waves 10 or can correlate with this. In the volume portion 8, the solid body has a thickness, a transmission and / or a crystal parameter. Each volume portion 8 may have a first surface portion of the first surface 4 and then extend to the second surface 6, where the volume portion 8 may have a second surface portion of the second surface 6. For example, the thickness / transmission / crystal parameter in the volume portion 8 corresponds to a thickness / transmission / crystal parameter of the solid body averaged over a lateral extent of the volume portion 8. For example, the first surface 4 is exposed to the light waves 10.At least a portion of the light waves 10 can be reflected at the first surface 4 and at least a further portion of the light waves 10 can be coupled into the solid body 2. A portion of the light waves 10 coupled into the solid body can be at least partially reflected at the second surface 6. For example, the light waves 10 at the second surface 6 are at least partially reflected at the component structures 16 and / or the metallization 161. The light waves 11 reflected on the first surface 4 and on the second surface 6 can subsequently be detected at least partially by the sensor device 12. In particular, light parameters of the reflected light waves 11 are detected with the sensor device 12.It is possible that different wavelengths and / or polarizations of the light waves 10 in the solid body 2 experience a different propagation in the vertical direction z and / or a different absorption in and / or reflection at the solid body 2 (indicated in FIG. 1 by a varying hatching within the volume portion 8). In particular, the light waves can be fanned out. For example, it is possible that the shorter wavelength focus position (represented by narrower hatching) is located closer to the first surface 4 than the longer wavelength focus position (represented by wider hatching). The light waves 11 reflected at the first surface 4 and at the second surface 6 can overlap. Temporal differences of the spectral components and / or of the polarization components can result from the wavelength-dependent propagation. From such differences, it is possible, for example, to draw conclusions about the distance between the first surface 4 and the second surface 6 and / or the transmission and / or the crystal parameters and / or the position of the modifications 1 in the volume portion 8. For example, confocal chromatic distance measurement can be performed.In general, information (e.g. distance information, intensity information, polarization information, location information, color information) can be determined from the light parameters detected by means of the sensor device 12. The information can be used to determine a parameter of the solid body 2 in the volume portion 8 (e.g. thickness, transmittance, crystal parameter) and / or a parameter of the modifications 1 in the volume portion 8 (e.g. position, gloss image).In the method, modifications 1 are furthermore produced in the volume portion 8 of the solid body 2 by means of the laser device 13. For example, the laser radiation 14 is focused into the solid body 2 for this purpose, wherein the material of the solid body 2 is damaged (e.g. melted) at the focus position 26. For example, the damage takes place by means of a multiphoton process. At least one laser parameter of the laser radiation 14 is set in the volume portion 8 as a function of the previously determined parameter (e.g. thickness, transmittance, crystal parameter) in such a way that the at least one modification 1 has a predefined distance from the second surface 6. The laser radiation 14 can be introduced into the solid body 2 via the first surface 2. Depending on the said parameter, e.g. a deflection of a part of the laser device 13, in particular of a part of the optics, in the vertical direction z can be effected by means of a control device 20.The method can comprise the analysis of a plurality of volume fractions 8, wherein distance information can be determined for each volume fraction 8. The individual volume portions 8 may be laterally adjacent to each other (e.g. adjacent to each other) or may partly or mostly overlap. It is possible that for each of the volume portions 8 the position (in particular the lateral position x, y) and / or the spatial position in the solid body 2 is determined. For example, a first volume portion 8 can be examined by means of a sensor assembly 22, while laser radiation 14 is introduced into a further volume portion 8 in dependence on the captured light parameters and the determined distance information, in particular the determined thickness in the further volume portion 8, in order to generate at least one modification 1.With a method described here, it is possible, for example, to introduce a multiplicity of modifications 1, in particular along a modification plane, into the solid body 2. In general, the predefined distance of each of the modifications 1 to the second surface 6 can be the same for all volume portions 8 of the solid body 2.Purely by way of example, the first surface 4 is illustrated inclined with respect to the second surface 6 in FIG. 1 (so-called wedge-shaped shape). The thickness variation resulting therefrom can be compensated for by a method described here, for example, in such a way that in a thicker region the modifications 1 have a greater distance from the first surface 4 than in a thinner region of the solid body 2. The modification plane can be generated parallel or substantially parallel to the second surface 6. The modifications 1 may be arranged or generated closer to the second surface 6 than to the first surface 4. the distance between the modifications 1 and the second surface 6 may be smaller (e.g. at most 90% or at most 80%) than the distance of the modifications 1 to the first surface 4.In the edge region, the solid body 2 has an optional notch 28. This notch 28 can be produced over the full circumference at the level of the modifications 1. For example, the modification plane can thereby be extended as far as the edge of the solid body 2.In some embodiments, the modification 1 may be a modification of silicon carbide (SiC). Modification 1 may be a locally limited phase change of SiC. Locally limited means, for example, that the phase conversion can be less than 1 mm 3 or less than 0.1 mm 3 or less than 0.01 mm 3. The phase conversion can take place at the focus 26 of the laser radiation 14 and / or can result from a multiphoton excitation. The modifications 1 may be partially overlaid and / or spaced apart from each other. The modifications 1 can result in compressive stresses in the solid body 2, as a result of which the solid body can tear in the region of the modification 1, in particular can tear subcritically. Subcritical can mean that a crack (also referred to as a microcrack) of a maximum length of less than 5 mm, in particular of less than 2 mm or less than 1 mm, forms.The cracks can be connected to one another, for example, by applying a force to the solid body 2. The joining of the cracks may result in the separation of a solid layer from the solid 2. By connecting the cracks, a solid layer 3 can be separated from the solid 2, in particular along the detachment plane. The solid layer 3 can be thinner than the residual solid resulting from the separation of the solid layer 3 from the solid 2. After the severing, the regions of the solid body 2 having the cracks are then exposed, for example.The force can be introduced into the solid body 2 for example by means of waves, in particular sound waves, and / or by a mechanical load and / or by generating stresses. For example, in order to generate stresses and / or a mechanical load, a polymer layer (in particular a polymer layer comprising PDMS) is arranged on the first surface 4 and then cooled. In some embodiments, the polymer layer may be cooled to a temperature that is below a glass transition temperature of at least one component of the polymer layer.FIG. 2 shows an exemplary representation of values detected and / or detected by means of the sensor device 12. For example, the values (here: wavelength-dependent intensity) correspond to the light parameters or are part of the light parameters or at least part of the light parameters is determined from the values. Here, the intensity 38 of the reflected and detected light waves 11 is plotted as a function of the wavelength of the reflected and detected light waves 11. At a first wavelength λ 1 the spectrum has a first peak with a first intensity I 1. At a second wavelength λ 2 the spectrum has a second peak with a second intensity I 2. The first peak may correspond to a portion of the reflected light waves 11 reflected at the first surface 4 and the second peak may correspond to a portion of the reflected light waves 11 reflected at the second surface 6. For example, from the first peak (in particular its spectral position, i.e. first wavelength λ 1) a first distance D 1 to the first surface 4 and from the second peak (in particular its spectral position, i.e. second wavelength λ 2) a second distance D 2 to the second surface 6 can be determined-in each case only from the spectral position of the respective peak or in combination with further light parameters. The difference of the first intensity I 1 and the second intensity I 2 can correspond to the absorption in the volume portion 8. From the absorption, alone or in combination with further light parameters, for example, the transmission in the volume portion 8 can be determined.The spectral distance 36 of the two peaks can be correlated to the thickness in the volume portion 8. Depending on this information, the focus position 26 of the laser radiation 14 can be set very precisely, in particular for compensating a variation of the thickness along the lateral position x, y.

Claims

A method for creating modifications (1) inside a solid body (2), comprising the steps of: providing the solid body (2), wherein the solid body (2) has a first surface (4) and a second surface (6) spaced apart from the first surface (4) in a vertical direction (z), wherein a thickness of the solid body (2) is a function of a lateral position (x, y) along the first surface (4) and / or along the second surface (6); applying light waves (10) of different wavelengths to a volume portion (8) of the solid body (2) via the first surface (4), wherein the light waves are partially reflected at the first surface (4) and are partially coupled into the solid body (2) and reflected at the second surface (6); At least partial detection of light parameters of the reflected light waves (11) with a sensor device (12) and determination of distance information from at least part of the detected light parameters; determination of a thickness of the solid body (2) in the volume portion (8) of the solid body (2) from the distance information; introduction of laser radiation (14) into the volume portion (8) of the solid body (2) via the first surface (4) to generate modifications (1) in the interior of the solid body (2), wherein at least one laser parameter of the laser radiation (14) is set at least depending on the thickness of the volume portion (8) such that the modifications (1) have a predefined distance from the second surface (6), the modifications are generated within a detachment plane, and wherein the detachment plane is aligned parallel or at an angle of at most 4° to the second surface (6).Method according to Claim 1, wherein the captured light parameters comprise intensities of the reflected light waves and detected by means of the sensor device (12), wherein intensity information is determined from the intensities and wherein the at least one laser parameter is set as a function of the intensity information.Method according to claim 2, wherein for the detection of the light parameters the reflected light waves are detected at the same volume portion (8) at least twice with the sensor device (12), wherein the reflected light waves (11) are detected at least twice for different lengths, wherein a comparison of the intensity information is carried out, which represents the light waves detected for different lengths.Method according to claim 2 or 3, wherein the determination of the thickness and the determination of the intensities of the light waves for the same portion of the solid body (2) is effected within a time window of less than 2 seconds.A method for creating modifications (1) inside a solid body (2), comprising the steps of: providing the solid body (2), the solid body having a first surface (4) and a second surface (6) spaced apart from the first surface (4) in a vertical direction (z), wherein a transmittance of the solid body (2) is a function of a lateral position (x, y) along the first surface (4) and / or along the second surface (6); applying light waves (10) of different wavelengths to a volume portion (8) of the solid body (2) via the first surface (4), wherein the light waves are partially reflected at the first surface (4) and are partially coupled into the solid body (2) and reflected at the second surface (6); At least partial detection of light parameters of the reflected light waves (11) with a sensor device (12) and determination of intensity information from at least part of the detected light parameters; determination of a transmittance of the solid body (2) in the volume portion (8) of the solid body (2) from the intensity information; introduction of laser radiation (14) into the volume portion (8) of the solid body (2) via the first surface (4) for generating at least one modification (1) in the interior of the solid body (2), wherein at least one laser parameter of the laser radiation (14) is set at least depending on the transmittance of the volume portion (8) such that the at least one modification (1) has a predefined distance from the second surface (6).Method according to Claim 5, wherein, for the detection of the light parameters, the reflected light waves (11) are detected at the same volume portion (8) at least twice with the sensor device (12), wherein the reflected light waves (11) are detected at least twice for different lengths, wherein the intensity information representing the light waves detected for different lengths is matched.Method according to claim 5 or 6, wherein a thickness of the solid body (2) is a function of a lateral position (x, y) along the first surface (4) and / or along the second surface (6) and wherein distance information is determined from at least a part of the detected light parameters, wherein a thickness of the solid body (2) in the volume portion (8) of the solid body (2) is determined from the distance information; wherein the at least one laser parameter is additionally set depending on the thickness of the volume portion (8).Method according to one of claims 2, 3, 4, 6 or 7, wherein the at least one laser parameter comprises the energy of the laser radiation (14) and the focus position (26) of the laser radiation (14).Method according to one of Claims 5 to 8, wherein the captured light parameters comprise polarizations of the reflected light waves (11) detected by means of the sensor device, wherein polarization information of the volume portion is ascertained from the polarizations, and wherein the at least one laser parameter is set as a function of the polarization information.Method according to one of the preceding claims, further comprising the steps of: applying, at least after the generation of the modification (1) in the volume portion (8), the volume portion (8) of the solid body (2) with the light waves (10) of different wavelengths and / or with further light waves of different wavelengths via the first surface (4), wherein the light waves (10) and / or the further light waves are partially reflected at the first surface (4) and are partially coupled into the solid body (2) and reflected at the at least one modification (1); at least partially detecting light parameters of the reflected light waves (11) and / or the reflected further light waves with a sensor device (12) and / or a further sensor device, determining location information from at least a part of the detected light parameters; determining a distance between the at least one modification (1) and the first surface (4) and / or between the at least one modification (1) and the second surface (6) in the volume portion (8) of the solid body (2) from the location information.Method according to one of the preceding claims, wherein the sensor device (12) and a radiation source (9) by means of which the light waves (10) are generated are arranged closer to the first surface (4) than to the second surface (6).Method according to one of the preceding claims, wherein, for the solid body (2), the distance information and / or the intensity information and / or the thickness and / or the transmittance and / or the detected light parameters are stored on a data carrier as reference data at least as a function of the lateral position along the first surface (4) and / or the second surface (6) and / or as a function of the volume proportion (8).Method according to one of the preceding claims, wherein the solid body (2) has component structures (16) of a semiconductor component on the second surface (4).Method according to one of the preceding claims, wherein the method is used for separating a solid-state layer (3) from the solid-state body (2) and / or for producing a semiconductor component.Apparatus for carrying out a method according to one of the preceding claims, at least having a radiation source (9) for generating light waves (10) of different wavelengths in a predefined spectrum, a sensor device (12) for detecting light parameters of at least part of the light waves (10), a programmable circuit comprising an input for receiving sensor signals from the sensor device (12), a processing unit for determining at least one of the following information from the detected light parameters: distance information, intensity information, location information, polarization information, and an output for outputting the information determined by the processing unit, a laser device (13) for generating laser radiation (14) for generating modifications (1) in the interior of the solid body (2), a drive unit (20) for driving the laser device (13) as a function of the information determined by the processing unit, wherein the laser device (13) is configured to change at least one laser parameter of the laser radiation (14) as a function of the information determined by the sensor device (14) such that the modifications are generated within a detachment plane, and the detachment plane is aligned parallel or at an angle of at most 4° to the second surface (6), or wherein at least one laser parameter of the laser radiation (14) is adjusted at least as a function of the transmittance of the volume portion (8) such that the modifications (1) have a predefined distance from the second surface (6).Apparatus according to the preceding claim, wherein the radiation source (9) and the sensor device (12) form a sensor assembly (22), wherein the sensor assembly (22) is arranged in a fixed relative position to the laser device (13).The device according to the preceding claim, wherein at least one second sensor assembly (24) is provided, wherein the second sensor assembly (24) also comprises a radiation source (9) and a sensor device (12), wherein the first sensor assembly (22), the second sensor assembly (24) and a component of the optics of the laser device (13), by means of which the laser radiation (14) is focused into the solid body (2), are arranged in a straight line, wherein the component of the optics of the laser device (13) is arranged between the sensor assemblies (22, 24).Programmable circuit as part of the device according to one of claims 15 to 17.A computer program product comprising instructions for programming a programmable circuit according to claim 18 and / or for driving an apparatus for carrying out the method steps according to claim 1 and / or claim 5.

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