Method for thinning solid body layers provided with components

Abstract

The present invention relates to a method for separating at least one solid-body layer (4) from at least one solid body (1). Thereby, the method as claimed in the invention comprises the steps: creating a plurality of modifications (9) by means of laser beams within the interior space of the solid body (1) to form a detachment plane (8), producing a composite structure by arranging or producing layers and/or components (150) on or above an initially exposed surface (5) of the solid body (1), wherein the exposed surface (5) is an integral part of the solid-body layer (4) to be separated, introducing an external force into the solid body (1) for generating tensions within the solid body (1), wherein the external force is so strong that the tensions initialize a crack propagation along the detachment plane (8), wherein the modifications for forming the detachment plane (8) are created before producing the composite structure.

Claims

1. A method for separating a solid-body layer from a solid body, the method comprising: creating a plurality of modifications by means of laser beams within an interior space of the solid body to form a detachment plane; after creating the plurality of modifications, producing a composite structure by arranging or producing layers and/or components on or above an initially exposed surface of the solid body, the exposed surface being an integral part of the solid-body layer to be separated; and introducing an external force into the solid body for generating tensions within the solid body, the external force causing the tensions to initialize a crack propagation along the detachment plane, wherein introducing the external force comprises: thermally applying a receiving layer comprising a polymer material on an exposed surface of the composite structure or the solid-body layer to be separated, so that the tensions are mechanically generated; and cooling the receiving layer to a temperature under ambient temperature, so that the polymer material of the receiving layer completes a glass transition and a crack in the solid body spreads along the detachment plane due to the mechanically generated tensions, the crack separating the solid-body layer from the solid body.

2. The method of claim 1, wherein the receiving layer is thermally applied to a surface of the solid body opposite from the surface at which the layers and/or components for forming the composite structure are arranged.

3. The method of claim 1, wherein the receiving layer comprises a polymer material having a glass transition between −130° C. and 0° C. or a polymer-hybrid material which forms a polymer matrix with a filler in the polymer matrix.

4. The method of claim 1, wherein the receiving layer is cooled to a temperature between −130° C. and −10° C. via nebulized nitrogen, a nitrogen bath or by a nitrogen spray.

5. The method of claim 1, further comprising: forming a stabilization layer on an exposed layer or exposed components of the composite structure, the stabilization layer limiting deformations of the exposed layer or of the exposed components which result from the mechanically generated tensions.

6. The method of claim 5, wherein the stabilization layer comprises a ceramic material and/or comprises a polymer material.

7. The method of claim 5, wherein the stabilization layer is formed in-situ or provided as a film, and/or wherein the stabilization layer infuses the exposed layer or the exposed components, and/or wherein the stabilization layer is removed from the exposed layer or the exposed components by applying a solvent or by dipping into a solvent.

8. The method of claim 5, wherein the stabilization layer is a glass wafer or a glass wafer is arranged on the stabilization layer.

9. The method of claim 1, further comprising: before creating the detachment plane, treating the solid body using a high-temperature method executed at a temperature between 70° C. and the melting temperature or evaporation temperature of the solid body, wherein the high-temperature method is an epitaxy method, a doping method or a plasma method, wherein at least one layer is produced on the solid body by the high-temperature method, wherein the at least one produced layer has predefined parameters, at least one of the predefined parameters being a maximum degree of breakage and/or absorption and/or reflection of laser-light waves, the degree of breakage and/or absorption and/or reflection is under 5%.

10. The method of claim 1, wherein pressure tensions in the solid body are generated by the modifications and at least components of the modifications generating the pressure tensions remain on the solid-body layer when separating the solid-body layer from the solid body.

11. The method of claim 10, further comprising: producing, by sputtering or electrochemical deposition, a metal layer on a surface exposed by separation of the solid-body layer from the solid body.

12. The method of claim 11, wherein the metal layer is produced on the solid-body layer in a first physical state and at a temperature above room temperature and is at room temperature in a second physical state, and wherein due to a transition from the first physical state into the second physical state, the metal layer impinges the solid-body layer for at least partial compensation of the deformation caused by the pressure tensions of the modification components remaining on the solid-body layer.

13. The method of claim 11, wherein the metal layer is produced on the solid-body layer at a temperature range having a minimum temperature of at least 100° C. above room temperature and a maximum temperature of 2,000° C. or lower than the melting or evaporation temperature of the solid-body material.

14. The method of claim 1, wherein creating the plurality of modifications comprises: creating a plurality of basic modifications using predefined process parameters; and creating initialization modifications to initialize subcritical cracks, at least one process parameter for creating the initialization modifications being different from at least one of the process parameters for creating the basic modifications.

15. The method of claim 14, wherein the initialization modifications are created in one direction which is inclined towards or spaced away from a progression of a line along which the basic modifications are created.

16. The method of claim 14, wherein the subcritical cracks spread in the solid body between 5 μm and 200 μm.

17. The method of claim 14, wherein sections crack between regions having a plurality of lines in which the subcritical cracks have propagated.

18. The method of claim 1, wherein the solid-body material is silicon or SiC.

19. A method for creating electrical components, the method comprising: creating a plurality of modifications by means of laser beams within an interior space of a solid body to form a detachment plane, so that pressure tensions within the solid body are generated by the plurality of modifications, producing a composite structure by arranging or producing layers and/or components on or above an initially exposed surface of the solid body, the exposed surface being an integral part of a solid-body layer to be separated from the solid body; separating the solid-body layer from the solid body along the detachment plane, wherein at least components of the plurality of modifications which generate the pressure tensions remain on the solid-body layer, wherein so many modifications are created that the solid-body layer separates from the solid body or an external force is introduced into the solid body for generating other tensions within the solid body, the external force causing the tensions to form a crack propagation along the detachment plane formed by the plurality of modifications; and producing a metal layer on a surface exposed by the separation of the solid-body layer from the solid body, to at least partially compensate for the pressure tensions caused by modification components, wherein the external force is introduced into the solid body by: thermally applying a receiving layer comprising a polymer material on an exposed surface of the composite structure or the solid-body layer to be separated, so that the pressure tensions are mechanically generated; and cooling the receiving layer to a temperature under ambient temperature, so that the polymer material of the receiving layer completes a glass transition and a crack in the solid body spreads along the detachment plane due to the mechanically generated is introduced into the solid body tensions, the crack separating the solid-body layer from the solid body.

20. The method of claim 19, wherein the electrical components are Schottky diodes and/or transistors, wherein the metal layer forms an ohmic contact and/or an interface for heat dissipation, and wherein on average, per cm.sup.2 of a level surface side of the solid-body layer, at least 4 electrical components are produced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The figures show:

(2) FIG. 1a-f treatment sequence according to the invention;

(3) FIG. 2a-b two schematic examples of solid-body arrangements as they can be provided according to the invention;

(4) FIG. 3a-i other schematic examples for solid-body arrangements according to the invention and solid body arrangements that can be produced within the scope of the method according to the invention, as an intermediate product;

(5) FIG. 4 a schematic illustration of two lines formed by modifications;

(6) FIG. 5a-d various cooling devices that are preferably usable for cooling within the scope of the method according to the invention;

(7) FIG. 6a-c three different schematic examples for the crack propagation between modifications;

(8) FIG. 7 differently oriented modification lines for initializing different functions;

(9) FIG. 8 an example of a Schottky diode;

(10) FIG. 9 an example of a MOSFET and

(11) FIG. 10a-b the production of depressions extending into the interior space of the solid body from the edge, wherein the depressions preferably extend along a detachment plane defined by modifications 9.

DETAILED DESCRIPTION

(12) FIG. 1a shows the provision of the solid body 1, in particular, of a wafer.

(13) In accordance with FIG. 1b, the provided solid body 1 is coupled or glued or welded or screwed or clamped to a tool carrier (chuck) 3, wherein the tool carrier preferably comprises a cooling function and thereby preferably being transformed into a cooling device 3. The solid body 1 is preferably fixed in the longitudinal direction with its underside, which preferably lies in the longitudinal direction opposite to the surface 5, to the cooling device 3, in particular, being glued. The laser beams are thereby introduced into the solid body 1 via the surface 5, which is an integral part of the solid-body layer to be separated, for creating modifications 9 in the direction of the cooling device 3. Being particularly preferred, furthermore, a high-temperature treatment of the surface 5 takes place, in particular an epitaxial material arrangement on the solid-body surface 5, thereby preferably resulting in another layer 145 or a plurality of other layers 145. The at least one high-temperature method is preferably an epitaxy method, a doping method or a method under the use of plasma, wherein at least one layer 145 is created on the solid body 1 by means of the high-temperature method, in particular, in the case of an epitaxy method, wherein the at least one produced layer 145 has predefined parameters, wherein at least one predefined parameter specifies a maximum degree of breakage and/or absorption and/or reflection of laser-light waves, wherein the degree of breakage and/or absorption and/or reflection is under 5% and preferably under 1% and, being particularly preferred, under 0.1%. Furthermore, the produced layer 145 or the other produced layers 145 are preferably free of metal.

(14) FIG. 1c schematically shows the creation of modifications 9 by means of the laser beams. The laser beams thereby preferably penetrate into the solid body 1 via a layer 145, which was previously produced by means of the high-temperature method. As an alternative however, it is conceivable that the laser beams penetrate into the solid body 1 via an exposed, meaning a surface of the solid body 1 that is not coated with the other layer 145, in particular from below. Thereby, the solid body 1 is preferably held on the side or on the external ends (width and/or depth direction).

(15) FIG. 1d shows a schematic sectional illustration of the solid body 1 after the creation of the modifications 9. In accordance with this example, four blocks of modifications 9 can be recognized, which lead to the four crack parts 25, 27, 28, 29. Adjacent to the blocks with modifications 9, the reference numbers 41, 42, 43, 44 and 45 each identify regions without modifications 9 or regions, in which fewer modifications 9 are created than in the regions, in which the blocks of modifications 9 are produced.

(16) FIG. 1e shows a state, in accordance with which a receiving layer, in particular, comprising a polymer material, is arranged or produced on other components (not shown) arranged on the surface 5 or on another layer previously epitaxially created on the surface 5. The receiving layer is preferably created as a film and after its creation, coupled to the surface 5, in particular, bonded or glued on. However, it is also possible to form the receiving layer by applying a liquid polymer onto the surface 5 and then allowing it to solidify.

(17) Between the step of creating the modifications and attaching the receiving layer, preferably an arrangement or a creation of other layers 150 and/or components 150 takes place on the surface 5 or on another layer 145 already created on it during an upstream high-temperature method.

(18) FIG. 1f schematically shows a tempering of the receiving layer. The receiving layer is preferably tempered, in particular cooled, to a temperature below the ambient temperature, in particular, to a temperature of less than 20° C., or less than 1° C., or less than 0° C., or less than −10° C., or less than −50° C., or less than −60° C. Wherein the material of the receiving layer 140 experiences a glass transition or a crystallization due to the cooling. Preferably, the tempering of the receiving layer takes place by means of a liquid nitrogen, in particular, by means of a nitrogen vapor. Due to the tempering, in particular, due to the glass transition, the receiving layer contracts, whereby mechanical tensions in the solid body 1 are generated. Due to the mechanical tensions, a crack is initialized that connects the crack portions 25, 27, 28, 29, by means of which the solid-body portion 12 is separated from the solid body 1.

(19) FIG. 2a shows an embodiment, in accordance with which the receiving layer 140 is arranged on a surface of the solid body, which is further spaced away from the modifications than a surface 5 that is parallel or preferably, essentially parallel or completely parallel thereto. Preferably, the surface comprises another layer 145 (analogous to FIG. 1b-1f). Preferably, components 150 or other material layers 150 are arranged on the other layer 145 or on the exposed surface 5. Preferably, a stabilization layer and/or a protective layer 142 is arranged or produced on an exposed surface of the other material layer 150 or the components 150. Thereby, the components 150 can be casted, in particular using a polymer material and/or ceramic material. In addition, it is conceivable that a stabilization device, in particular a further wafer, such as a glass wafer, is coupled to the stabilization layer and/or protective layer 142, in particular, being glued or bonded on. The stabilization layer and/or protective layer 142 or the stabilization layer and/or protective layer 142 and the stabilization device cause that the components 150 or other material layer 150 only deform insignificantly during splitting or after splitting or do not deform at all. When split, the deformation can be caused by the forces generated by the receiving layer 140 and after splitting, deformation can be caused by the remaining modifications, in particular, material conversions. In the case of a material conversion, the modifications cause that pressure forces arise, whereby a bowing of the separated solid-body layer would result without the stabilization layer/stabilization device. In addition, or as an alternative, the stabilization layer 142 can be designed as a glass wafer or, in addition or as an alternative, a glass wafer can be arranged on the stabilization layer 142.

(20) A unit consisting of a separated solid-body layer and a stabilization layer and/or protective layer 142 arranged on it and, possibly, a stabilization device arranged on it, is then preferably further treated to remove stress. Being particularly preferred, the stabilization layer 142 or the stabilization device forms a holding device, by means of which the separated solid-body layer is fixable for a material removal treatment with relation to a material removal device, in particular, a grinding and/or polishing device. By means of the material removal device, the modification portions remaining on the separated solid-body layer are then removed, in particular, removed by machining.

(21) Within the context of the invention, the solid-body layer is preferably always thinner than the remaining solid-body portion. Furthermore, it is conceivable that the receiving layer is not arranged or produced on a surface of the later solid-body layer, but on a surface of the remaining solid-body portion. If the solid-body material is silicon, then, with relation to the remaining solid body, the separated solid-body layer preferably has a level less than 40% of the level of the remaining solid body, in particular, less than 30% or 20% of the level of the remaining solid body. In the case of silicon, preferably, predetermined parameters for the modification creation are provided; the numerical aperture is preferably between 0.5 and 0.8, in particular at 0.65, the radiation depth is between 150 μm and 1000 μm, in particular, at 300 μm, the pulse interval is between 1 μm and 5 μm, in particular at 2 μm, the line spacing is between 1 μm and 5 μm, in particular at 2 μm, the pulse duration is between 50 ns and 400 ns, in particular, at 300 ns and the pulse energy is between 3 μJ and 30 μJ, in particular at 10 μJ.

(22) If the material is SiC, then, with relation to the remaining solid body, the separated solid-body layer preferably has a level less than 50% of the level of the remaining solid body, in particular, less than 45% or 40% or 35% or 30% or 25% of the level of the remaining solid body. In the case of SiC, preferably, predetermined parameters for the modification creation are provided; the numerical aperture is preferably between 0.4 and 0.8, in particular at 0.4, the radiation depth is between 50 μm and 500 μm, in particular, at 180 μm, the pulse interval is between 0.1 μm and 3 μm, in particular, at 1 μm, the line spacing is between 10 μm and 100 μm, in particular, at 75 μm, the pulse duration is preferably between 1 fs and 10 ns, in particular, at 3 ns and the pulse energy is between 0.5 μJ and 30 μJ, in particular at 7 μJ.

(23) Also, in FIG. 2b, analogously to FIG. 1b-1f, another layer 145 can be created, even if this has not been identified. The other material layers or components 150 are therefore preferably created or arranged on the other layer 145 or on an exposed surface of the solid body.

(24) Furthermore, FIG. 2b shows that the receiving layer can be arranged on a surface of the remaining solid body and another receiving layer 146 can be arranged on the components or other material layers 150. Thereby, the components can additionally be provided with a stabilization layer 142, whereby the other receiving layer 146 is preferably arranged or produced on the stabilization layer and/or protective layer 142. The other receiving layer 146 is preferably provided as a film and is preferably also made of at least partially of a polymer material. Being particularly preferred, the other receiving layer 146 comprises the same material as the receiving layer 140 or 142. This embodiment is favorable since the tensions for creating the crack can be introduced into the solid body from two sides.

(25) FIGS. 3a to 3i show different arrangements, which can be provided after creating the other material layers or components 150 for introducing the crack.

(26) FIGS. 3a-3i show diverse solid-body arrangements 176, as they are favorable for inducing crack formation and/or crack initialization tensions.

(27) Here, FIG. 3a shows a processed solid body 1 or wafer with structures or components 150.

(28) With relation to the solid body 1 shown in FIG. 3a, in the case of the solid body 1 shown in FIG. 3b, a receiving layer 140 is arranged or produced on the component side, in particular, on the components 150 or the other material layers 150. Here, the receiving layer 140 is preferably arranged on the solid-body layer to be separated. Thereby, the receiving layer 140 can also be referred to as split film and is thereby preferably laminated onto the structure side. In the subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or crack formation is initialized.

(29) With relation to the illustration in FIG. 3b, in accordance with FIG. 3c, a holding layer/bonded wafer is arranged on the underside of the solid body or on the exposed surface of the solid body. The holding layer can also have to do with a tool carrier or chuck 3. In the subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or crack formation is initialized.

(30) With relation to FIG. 3b, FIG. 3d shows an arrangement, in accordance with which the solid body is provided on both sides with receiving layers 140, 146. The other receiving layer 146 is arranged on a surface of the later remaining residual solid body, wherein an adhesive layer 148 and/or sacrificial layer 149 and/or protective layer 142 can be created or arranged between the other receiving layer 146 and the solid body 1. Both receiving layers 140 and 146 are preferably laminated on. In the subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or crack formation is initialized.

(31) FIG. 3e shows an arrangement, in accordance with which no adhesive layer 148 and/or sacrificial layer 149 and/or protective layer 142 is arranged or produced between the other receiving layer 146 and the solid body 1 with relation to the arrangement known from FIG. 3d. In the subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or crack formation is initialized.

(32) FIG. 3f shows an arrangement that is structured inversely to the arrangement known from FIG. 3d, meaning that the adhesive layer 148 and/or sacrificial layer 149 and/or protective layer 142 is not arranged or produced between the other receiving layer 146 and the solid body 1, but is/are created or arranged between the receiving layer 140 and the solid body 1 and thereby, on the solid-body layer to be separated. On components 150 or the structures, for example, one or a plurality of layers can be created by spin coating for example. As a subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or the crack formation is initialized.

(33) FIG. 3g shows an arrangement or a form, which corresponds to a combination of the arrangements in FIGS. 3d and 3f. The solid body is preferably laminated with split film on both sides, and, similarly, a protective layer and/or adhesive layer and/or sacrificial layer can be provided; furthermore, spin coating is also possible on the structures for example. As a subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or the crack formation is initialized.

(34) FIG. 3h shows an arrangement, which is similar to the arrangement shown in FIG. 3b, wherein the receiving layer is not arranged or laminated on a surface of the solid-body layer to be separated, but on one side of the residual solid body remaining after separation. The separation then takes place due to the cooling analogously to the separation of an ingot or like in an ingot process.

(35) FIG. 3i shows an arrangement, which is similar to the arrangement known from FIG. 3c, wherein one or a plurality of the layers or devices mentioned in the following is/are arranged or produced on the component side of the solid body or under the components 150. These layers or facilities preferably include: At least or exactly one adhesive layer 148 and/or at least or exactly one sacrificial layer 149 and/or at least or exactly one protective layer 142 and/or at least or exactly one stabilization device 3, in particular, a tool carrier or chuck or another wafer. As a subsequent step, a cooling of the total arrangement takes place, wherein the split and crack initialization and/or the crack formation is initialized.

(36) FIG. 4 shows an illustration of an example of a writing pattern in the case of an X-Y processing:

(37) Arrows 170, 172 represent the laser feed direction, the black circles represent the various laser shots or modifications 9, which do not overlap here with their harmful effect within the material. Thereby, it is preferred if the laser initially moves into one direction and creates modifications 9 before it reverses and writes modifications 9 in the second (lower) direction.

(38) FIGS. 5a to 5d show different cooling devices 174. The solid-body arrangements 176 processed in these cooling devices 174 result from the various manifestations and designs described in FIGS. 1a to 3i of the solid bodies 1 provided with one or a plurality of receiving layer(s) 140, 146. The cooling devices 174 shown herein all use a liquefied gas 178 as an initial cooling medium for cooling. This initial cooling medium is either nebulized or vaporized depending on the embodiment. Preferably, the initial cooling medium has to do with liquid nitrogen. Alternative cooling methods, for example, using peltier elements, are also conceivable and possible.

(39) Thereby, the cooling device 174 is preferably used to cool the receiving layer 140, 146 to a temperature between −130° C. and −10° C., in particular, to a temperature between −80° C. an −50° C.

(40) In accordance with FIG. 5a, the cooling device 174 comprises a nitrogen bath, wherein the receiving layer is positioned at a distance away from the liquid nitrogen held in the nitrogen bath, in particular, by means of an adjustable positioning device 180. Thereby, the solid-body arrangement is preferably arranged on a positioning device or on a holder over the nitrogen bath. This results in a temperature gradient above the chamber height and the temperature at the solid-body arrangement can be adjusted via the filling height with the initial cooling medium or the position of the solid-body arrangement 176 (spacing from the bottom of the chamber).

(41) In accordance with the embodiments in FIGS. 5b to 5d, the cooling device preferably comprises a nebulizing means, in particular, at least or exactly one perforated pipeline for nebulizing liquid nitrogen or a nebulizing means for nebulizing liquid nitrogen and the cooling effect is created by means of nebulized or vaporized nitrogen.

(42) In accordance with FIG. 5b, preferably, a homogeneous spraying device/nebulizer for spraying or nebulizing is provided. Spraying or nebulizing preferably takes place above the solid-body arrangement 176. Furthermore, preferably, temperature measurements for temperature control take place, which output the output data for regulating a valve, in particular, a nitrogen valve. The temperature measurements preferably take place on the substrate or on the solid body 1 or on the receiving layer 140.

(43) The substrate or the solid body 1 or the solid-body arrangement 176 preferentially rests over the chamber bottom in order to avoid nitrogen settling at the bottom of the chamber.

(44) In accordance with FIG. 5c, preferably, a perforated pipeline is used as a homogeneous spraying device. Furthermore, preferably, temperature measurements for temperature control take place, which output the output data for regulating a valve, in particular, a nitrogen valve. The temperature measurements preferably take place on the substrate or on the solid body 1 or on the receiving layer 140.

(45) The substrate or the solid body 1 or the solid-body arrangement 176 preferentially rests over the chamber bottom in order to avoid nitrogen settling at the bottom of the chamber.

(46) In accordance with FIG. 5d, a cooling device 176 shows a homogeneous spraying device/nebulizer 182 for the cooling of preferably a plurality of sides or each side. Furthermore, preferably, temperature measurements for temperature control take place, which output the output data for regulating a valve, in particular, a nitrogen valve. The temperature measurements preferably take place on the substrate or on the solid body 1 or on the receiving layer 140.

(47) The substrate or the solid body 1 or the solid-body arrangement 176 preferentially rests over the chamber bottom in order to avoid nitrogen settling at the bottom of the chamber.

(48) The chamber 184 of the cooling device 174 is preferably sealed in order to reduce a temperature gradient as much as possible by means of insulation.

(49) FIG. 6 shows three examples for preferred correlations between the crystal lattice orientation and the modification creation. In particular, this method is useful for the separation of solid-body layers from a solid body comprising SiC or made of SiC. Due to these correlations, another method according to the invention results. This other method according to the invention is preferably used to separate at least one solid-body layer 4 from at least one solid body 1, in particular, from a wafer of an ingot or for thinning a wafer. Thereby, the other method according to the invention preferably comprises at least the steps: Creating a multitude of modifications 9 by means of laser beams in the interior space of the solid body 1 in order to form a detachment plane 8, and introducing an external force into the solid body 1 for generating tensions within the solid body 1, wherein the external force is so strong that the tensions cause a crack propagation along the detachment plane 8.

(50) According to the invention, the modifications are successively created in at least one line or row, wherein the modifications 9 made in a line or row are preferably created at a spacing X and with a height H so that a crack extending between two consecutive modifications, in particular, a crack extending in the crystal lattice direction, the crack propagation direction of which is aligned at an angle W to the detachment plane, connects both modifications to one another. The angle W is preferably between 0° and 6°, in particular, at 4°. Preferably, the crack extends from a region under the center of a first modification towards a region above the center of a second modification. The essential connection here is that the size of the modification can or must be changed depending on the spacing of the modifications and of the angle W.

(51) Furthermore, this method can also entail the step of producing a composite structure by arranging or producing layers and/or components 150 on or above an initially exposed surface 5 of the solid body 1, wherein the exposed surface 5 is preferably an integral part of the solid-body layer 4 to be separated. Being particularly preferred, the modifications for forming the detachment plane 8 are created before creating the composite structure.

(52) In order to introduce the external force, analogously to the previously described method, a receiving layer 140 can be arranged on an exposed surface 5 of the composite structure or of the solid body.

(53) The three FIGS. 6a to 6c are intended to illustrate how the size of the damage/modification zone amorphized/phase-transformed by the laser influences height having passed through the saw tooth pattern of the crack. In general, the crack extends along the crystal planes, meaning between individual atoms of the crystal. In the modified zone, these clear planes are no longer existent, so it comes to a stop.

(54) Due to a preferably highest numerical aperture possible, the damage zone can be made smaller along the beam direction as well as laterally on the focal plane. Since only the threshold intensity has to be achieved, a smaller pulse energy level is also sufficient here.

(55) If the damage zone is formed to be smaller in a suitable way, the laser modifications can be set more densely, which allows the saw tooth to run more briefly and, overall, a lower height extension of the modified plane results (first image).

(56) If, in contrast, the damage zone is larger (higher energy and/or lower numerical aperture—FIG. 6b)—the increased pressure of the amorphized zone also initializes a greater microcrack, which is made possible to catch (i.e. to stop in a controlled manner) with a damage zone with a greater extension at a greater spacing.

(57) FIG. 6c ultimately shows the danger if the damage zone is not sufficiently large and too far-reaching cracks are initialized by laser modification, the cracks run too far on the one hand—meaning the difference in height caused by the cracks becomes greater than desired—and, on the other hand, the cracks drift under the other damage zones and are not stopped by the amorphized material. This then leads to material losses again since all cracked material layers must be removed for the final product or for laser processing again.

(58) FIG. 7 shows a schematically presented snapshot from another method according to the invention. This other method is preferably used to separate at least one solid-body layer 4 from at least one solid body 1, in particular, to separate a wafer from an ignot or for thinning a wafer. Thereby, the other method according to the invention preferably comprises at least the steps: Creating a multitude of modifications 9 by means of laser beams in the interior space of the solid body 1 in order to form a detachment plane 8, and introducing an external force into the solid body 1 for generating tensions within the solid body 1, wherein the external force is so strong that the tensions cause a crack propagation along the detachment plane 8.

(59) According to the invention, at a first step, the modifications are created on a line 103 and preferably being at the same spacing to one another. Furthermore, it is conceivable that plurality of these lines created at the first step are created. Being particularly preferred, these first lines are created to be parallel to the crack propagation direction and, preferably to be straight or circularly arched in shape, in particular on the same plane. After creating these first lines, second lines 105 are preferably created to propagate and/or instigate preferably subcritical cracks. These second lines are also preferably created to be straight. Being particularly preferred, the second lines are inclined in relation to the first lines, in particular, being orthogonally oriented. The second lines preferably extend on the same plane as the first lines or, being particularly preferred, on a plane that is parallel to the plane, in which the first lines extend. Then, third lines are preferably created for connecting subcritical cracks.

(60) In particular, this method is useful for the separation of solid-body layers from a solid body comprising SiC or made of SiC.

(61) Furthermore, the modifications can be successively created in at least one line or row, wherein the modifications 9 made in a line or row are preferably created at a spacing X and with a height H so that a crack extending between two consecutive modifications, in particular, a crack extending in the crystal lattice direction, the crack propagation direction of which is aligned at an angle W to the detachment plane, connects both modifications to one another. The angle W is preferably between 0° and 6°, in particular, at 4°. Preferably, the crack extends from a region under the center of a first modification towards a region above the center of a second modification. The essential connection here is that the size of the modification can or must be changed depending on the spacing of the modifications and of the angle W.

(62) Furthermore, this method can also entail the step of producing a composite structure by arranging or producing layers and/or components 150 on or above an initially exposed surface 5 of the solid body 1, wherein the exposed surface 5 is an integral part of the solid-body layer 4 to be separated. Being particularly preferred, the modifications for forming the detachment plane 8 are created before creating the composite structure.

(63) In order to introduce the external force, analogously to the previously described method, a receiving layer 140 can be arranged on an exposed surface 5 of the composite structure or of the solid body.

(64) Thereby during the further course of the laser method according to the invention, lines that are parallel to the crack propagation direction (preferably referred to as transverse lines) are created on SiC (or also other materials) in order to define a plane for the preferred crack initialization before longitudinal lines cause the cracks. Here, the cracks are initially transversely initialized, then longitudinally before a final step sets lines between the longitudinal lines of the second step in order to initialize the cracks across the entire surface. This makes shorter cracking paths possible, which minimizes the final surface roughness. Sample image for cross lines (with the sawtooth) and crack propagation lines (on the sawtooth crests).

(65) FIG. 8 shows a Schottky diode 200 as an example. Thereby, this diode 200 preferably comprises a solid-body layer 4, which, in turn, comprises portions modified by means of laser radiation, in particular, modifications 9. The modifications 9 are thereby created in the proximity of a first surface of the solid-body layer 4. Thereby, a metal layer 20 is created on this first surface of the solid-body layer 4, in particular by means of a sputtering or a chemical deposition. The solid-body layer 4 comprises a second surface with relation to the first surface, on which another layer 145 is produced, in particular, by means of an epitaxy method. The solid-body layer 4 is thereby preferably made of a highly doped SiC or comprises a highly doped SiC and the produced layer 145 is preferably made of a weakly doped SiC or comprises weakly doped SiC. Weak-doped means preferably less doped than highly doped. Thereby, the produced layer 145 preferably comprises less doping than the solid-body layer 4 for each volume unit. Reference number 150 indicates a Schottky contact.

(66) FIG. 9 shows the structure of a MOSFET 250. This MOSFET 250 thereby preferably comprises a solid-body layer 4, which, in turn comprises portions modified by means of laser radiation, in particular, modifications 9. The modifications 9 are thereby created in the proximity of a first surface of the solid-body layer 4. Thereby, a metal layer 20 is created on this first surface of the solid-body layer 4, in particular by means of a sputtering or a chemical deposition. The metal layer 20 thereby forms a drain (high) via a connection 259. The solid-body layer 4 comprises a second surface with relation to the first surface. On the second surface, another layer, in particular n-type SiC is formed, in particular, being produced or arranged. Reference number 256 indicates another material or element, in particular p-type SiC. Reference number 254 stands for n+. Reference number 255 preferably indicates one or a plurality of channels, in particular, for conducting electrical current. The layer indicated with reference number 253 is preferably made of SiO.sub.2 or comprises such. Reference number 251 indicates a source (low) and reference number 252 indicates a gate.

(67) The present invention can thereby relate to a method for providing at least one solid-body layer 4, wherein the solid-body layer 4 is separated from a solid body 1. Thereby, the method according to the invention preferably comprises the steps:

(68) Creating a plurality of modifications 9 by means of laser beams within the interior space of the solid body 1 to form a detachment plane 8, wherein, pressure tensions within the solid body 1 are generated by means of the modifications 9, separation of the solid-body layer 4 by means of the separation of the remaining solid body 1 and of the solid-body layer 4 along the detachment plane 8 formed by the modifications 9, wherein at least components of the modifications 9 generating the pressure tensions remain on the solid-body layer 4, wherein so many modifications 9 are created that the solid-body layer 4 separates from the solid body 1 due to the modifications 9 or wherein an external force is introduced into the solid body 1 for generating other tensions within the solid body 1, wherein the external force is so strong that the tensions cause a crack propagation along the detachment plane 8 formed by the modifications, production of a material layer, in particular, a metal layer, on the surface exposed by the separation of the solid-body layer 4 from the solid body 1 for the at least partial and, preferably predominate and, being particularly preferred, full compensation of a deformation of the solid-body layer 4 caused by the pressure tensions of the remaining modification components or for the at least partial and preferably predominate or full compensation of the pressure tensions.

(69) As an alternative, the present invention can refer to a method for producing electrical components. This method preferably comprises the steps: creating a plurality of modifications 9 by means of laser beams within the interior space of a solid body 1 to form a detachment plane 8, wherein, pressure tensions within the solid body 1 are generated by means of the modifications 9, producing a composite structure by arranging or producing layers and/or components 150 on or above an initially exposed surface 5 of the solid body 1, wherein the exposed surface 5 is an integral part of the solid-body layer 4 to be separated, separation of the solid-body layer 4 by means of the separation of the remaining solid body 1 and of the solid-body layer 4 along the detachment plane 8 formed by the modifications 9, wherein at least components of the modifications 9 generating the pressure tensions remain on the solid-body layer 4, wherein so many modifications 9 are created that the solid-body layer 4 separates from the solid body 1 due to the modifications 9 or wherein an external force is introduced into the solid body 1 for generating other tensions within the solid body 1, wherein the external force is so strong that the tensions cause a crack propagation along the detachment plane 8 formed by the modifications, production of a metal layer 20 on the surface exposed by the separation of the solid-body layer 4 from the solid body 1 for the at least partial and, preferably, predominate and, being particularly preferred, full compensation of the pressure tensions caused by modification components.

(70) FIG. 10a shows an illustration, which shows a grinding tool 22 with a certain contour. If a level, straight or bent portion is spoken of with reference to the grinding tool, then a portion of the shown contour is always understood with this. Naturally, the grinding tool 22 can be designed, for example, as a rotary grinding tool, whereby the portions abutting the contour in the circumferential direction would preferably extend in a bent manner in the circumferential direction. The grinding tool 22 shown in the first illustration in FIG. 10a comprises a first processing portion 24, which comprises a bent main grinding surface 32 and comprises a second processing portion 26, which comprises a bent secondary grinding surface 34, wherein the radius of the main grinding service 32 is greater than the radius of the secondary grinding surface 34; preferably, the radius of the main grinding surface 32 is at least double, three times, four times or five times as big as the radius of the secondary grinding surface 34.

(71) According to the invention, thereby, in addition or as an alternative, a method for separating at least one solid-body layer 4, in particular, a solid-body disk or solid-body layer, is provided by a donor substrate 1 or solid body. Thereby, this method preferably comprises the steps:

(72) Providing a donor substrate 1, creating modifications 9 within the interior space of the donor substrate 1 by means of LASER beams, wherein a detachment region is specified by the modifications 9, along which a separation of the solid-body layer from the donor substrate 1 takes place, removal of the material of the donor substrate 1 starting from a surface extending in the circumferential direction of the donor substrate 1 towards the center (Z) of the donor substrate 1, in particular, for producing a circumferential depression, wherein the detachment region 8 or a detachment plane is exposed due to the material removal, separation of the solid-body layer 4 from the donor substrate 1, wherein the donor substrate is weakened in the detachment region by the modifications in such a way that the solid-body layer 4 detaches from the donor substrate 1 due to the material removal or, after material removal, such a number of modifications 9 are created that the donor substrate 1 is weakened in the detachment region in such a way that the solid-body layer 4 detaches from the donor substrate 1 or a tension generation layer 140 or receiving layer is produced or arranged on a surface of the donor substrate 1 that is aligned towards the circumferential surface in an inclined manner, particularly being level, and mechanical tensions are generated within the donor substrate 1 by a thermal application of the tension generation layer 140, wherein a crack results for separating a solid-body layer 4 due to the mechanical tensions, which spreads starting from the surface of the donor substrate exposed due to the material removal along the modifications 9. Here, it is possible that the modifications 9 are partly or completely created before the material removal or after the material removal. The depression 6 thereby preferably becomes narrower in the direction of the center Z towards a depression end 18. Preferably, the depression extends in a wedge shape, wherein the depression end 18 is preferably precisely on the plane, in which the crack expands or in which the modifications 9 are created. Furthermore, it is possible that a composite structure is created by arranging or producing layers and/or components 150 on or above an initially exposed surface 5 of the solid body 1, wherein the exposed surface 5 is an integral part of the solid-body layer 4 to be separated. Being particularly preferred, the modifications 9 for forming the detachment plane 8 are created before creating the composite structure.

(73) After creating the composite structure, introducing an external force into the solid body 1 preferably takes place for generating tensions within the solid body 1, wherein the external force is so strong that the tensions cause a crack propagation along the detachment plane 8.

(74) FIG. 10b shows an illustration, in accordance with which the modifications 9 shown in FIG. 10a, which, in particular, show amorphous portions of the crystal lattice, were treated by etching. Thereby, preferably an etching treatment of non-crystalline components of the solid body 1 takes place while the crystalline components of the solid body are not changed or not essentially changed by the etching treatment. Thereby, the effect is taken advantage of that etching methods can be selectively adjusted to crystalline-non-crystalline regions. Reference number 19 thereby indicates a region, in which the solid-body layer 4 is separated from the remaining residual solid body by means of an etching treatment of modifications 9. This solution is favorable since the mechanical crack opening is led deeper into the crystal by means of etching or etching on. This creates a more precisely defined crack start. Preferably, it applies that the thinner and the deeper the depression or the notch extends into the interior space of the solid body, the better it is with regard to the surface quality of a surface exposed due to a splitting of the solid-body layer. The etching parameters are chosen in such a way that non-amorphous parts, in particular a possibly polished top 5 and/or the unmodified edge 7 are not etched. Thereby, the method according to the invention can be supplemented by the step of an etching treatment or etching removal of the modifications 9 specifying the detachment region at least in sections for example, in particular with regard to the method described in FIG. 10a. The solid body 1, in particular prior to the creation of a composite structure, is preferably made of SiC or comprises SiC; preferably, the solid body comprises at least 95% (in terms of mass) or at least 99% (in terms of mass) or at least 99.99% (in terms of mass) SiC.

(75) Furthermore, it is pointed out that the material removal on the edge of the solid body, in particular with the subsequent etching step, can be added in the case of each method disclosed with this property rights document.