Splitting of a solid using conversion of material

Abstract

A method for creating a detachment zone in a solid is contemplated, such as in order to detach a solid portion, especially a solid layer, from the solid, said solid portion that is to be detached being thinner than the solid from which the solid portion has been removed. The method may comprise at least the steps of: providing a solid which is to be processed and which is made of a chemical compound; providing a LASER light source; and subjecting the solid to LASER radiation from the LASER light source so that the laser beams penetrate into the solid via a surface of the solid portion that is to be cut off; the LASER radiation controlling the temperature of a predefined portion of the solid inside the solid in a defined manner such that a detachment zone or a plurality of partial detachment zones is formed; characterized in that the temperature produced by the laser beams in a predefined portion of the solid is so high that the material forming the predefined portion is subject to modifications in the form of a predetermined conversion of material.

1 .- 15 . (canceled) 
     
     
         16 . A method for cutting off at least one solid portion from a solid, in particular a wafer, comprising:
 providing a solid, which is to be processed, wherein the solid is made of a chemical compound;   providing a LASER light source;   applying LASER radiation from the LASER light source to the solid,   wherein the laser beams penetrate into the solid via a surface of the solid portion, which his to be cut off,   wherein the laser radiation controls the temperature of a predefined portion of the solid inside the solid in a defined manner such that a detachment zone or a plurality of partial detachment zones is formed,   wherein the temperature produced by the laser beams in the predefined portion of the solid is so high that the material forming the predefined portion is subject to modifications in the form of a predetermined conversion of material.   arranging a receiving layer on the treated solid,   thermal application of the receiving layer for, in particular mechanically, generating crack expansion stresses in the solid, wherein a crack expands in the solid along the detachment zone due to the crack expansion stresses.   
     
     
         17 . The method according to  claim 16  further comprising the solid being of a chemical compound, such as silicon carbide, wherein the chemical compound preferably has a material or a plurality of materials chosen from the third, fourth and/or fifth main group of the periodic table of elements and/or from the  12   th  subgroup of the periodic table of elements. 
     
     
         18 . The method according to  claim 16  further comprising:
 the solid being connected to a cooling device via a solid surface, wherein the solid surface, which is connected to the cooling device, is embodied parallel or substantially parallel to the surface, via which the laser beams penetrate into the solid, and 
 the cooling device being operated as a function of the laser application, in particular as a function of the temperature control of the solid, which results from the laser application. 
 
     
     
         19 . The method according to  claim 18  further comprising the cooling device having at least one sensor device for capturing the temperature of the solid and, as a function of a predefined temperature course, effects a cool-down of the solid. 
     
     
         20 . The method according to  claim 18  further comprising the cooling device being coupled to a rotating means and the cooling device comprising the solid arranged thereon is rotated by means of the rotating means during the generation of the modifications, in particular with more than 100 revolutions per minute or with more than 200 revolutions per minute or with more than 500 revolutions. 
     
     
         21 . The method according to  claim 16  further comprising every material conversion effected by means of the LASER radiation represents a modification of the material of the solid and wherein:
 the solid is rotated with respect to the LASER light source and the number of the modifications per cm 2  of the solid surface per rotation, through which the LASER radiation penetrates into the solid in order to generate the modifications, is below a predefined maximum number, wherein the maximum number of the modifications per cm 2  and per rotation is preferably determined as a function of the solid material and of the energy density of the LASER radiation, and/or 
 the modifications are generated with different patterns, in particular distances between the individual newly generated modifications and/or with changed energy input, in particular reduced energy input, in response to consecutive rotations of the solid with respect to the LASER light source, and/or 
 the LASER light source is embodied as scanner and the generation of the modifications takes place as a function of the laser scanning direction, the laser polarization direction and the crystal orientation, and/or 
 the distance between the centers of two modifications, which are generated consecutively in modification generating direction or in circumferential direction of the solid is less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm, and/or 
 the outer limitations of modifications, which are generated consecutively in modification generating direction or in circumferential direction of the solid, are spaced apart from one another by less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm. 
 
     
     
         22 . The method according to  claim 16  further comprising the number of the generated modifications per cm 2  being different in at least two different zones of the solid and wherein:
 a first block of modifications is generated in a first zone, wherein the individual modifications per line are preferably generated spaced apart from one another by less than 10 μm, in particular less than 5 μm or less than 3 μm or less than 1 μm or less than 0.5 μm, 
 the individual lines of the first block are generated spaced apart from one another by less than 20 μm, in particular less than 15 μm or less than 10 μm or less than 5 μm or less than 1 μm, 
 a first partial detachment zone is formed by the first block of modifications, 
 a second block of modification lines is generated in a second zone, wherein the individual modifications per line are preferably generated spaced apart from one another by less than 10 μm, in particular less than 5 μm or less than 3 μm or less than 1 μm, or less than 0.5 μm, 
 the individual lines of the second block are generated spaced apart from one another by less than 20 μm, in particular less than 15 μm or less than 10 μm or less than 5 μm or less than 1 μm, wherein a second partial detachment zone is formed by the second block of modifications, 
 the first zone and the second zone are spaced apart from one another by a third zone, wherein no modifications or essentially no modifications or fewer modification as compared to the first or second zone per cm 2  are generated in the third zone by means of laser beams, and the first zone is spaced apart from the second zone by more than 20 μm, in particular more than 50 μm or more than 100 μm or more than 150 μm or more than 200 μm. 
 
     
     
         23 . The method according to  claim 22  further comprising the modifications at least in the first block and in the second block being generated in pulse intervals of between 0.01 μm and 10 μm and/or line spacings of between 0.01 μm and 20 μm are provided, and/or a pulse repetition frequency of between 16 kHz and 20 MHz is provided. 
     
     
         24 . The method according to  claim 16  further comprising an optics, by means of which the laser beams are guided from a laser beam source to the solid, being adapted as a function of the location, at which a modification is generated, from which at least one change of the numerical aperture is effected, wherein the numerical aperture at a location in the edge zone of the solid is smaller than at a different location of the solid, which is located closer to the center of the solid. 
     
     
         25 . The method according to  claim 16  further comprising the LASER radiation generating modifications, in particular crystal lattice defects, in the solid, and wherein:
 the solid is rotated with respect to the LASER light source, and 
 the number of the modifications per cm 2  of the solid surface per rotation, through which the LASER radiation penetrates into the solid in order to generate the modifications, is below a predefined maximum number, wherein the maximum number of the modifications per cm 2  and per rotation is preferably determined as a function of the solid material and of the energy density of the LASER radiation, and/or 
 the modifications are generated with different patterns, in particular distances between the individual newly generated modifications and/or with changed energy input, in particular reduced energy input, in response to consecutive rotations of the solid with respect to the LASER light source, and/or 
 the LASER light source is embodied as scanner and the generation of the modifications takes place as a function of the laser scanning direction, the laser polarization direction and the crystal orientation, and/or 
 the distance between the centers of two modifications, which are generated consecutively in modification generating direction or in circumferential direction of the solid is less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm, and/or 
 the outer limitations of modifications, which are generated consecutively in modification generating direction or in circumferential direction of the solid, are spaced apart from one another by less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm. 
 
     
     
         26 . The method according to claim  1  further comprising every material conversion, which is effected by means of the LASER radiation, represents a modification of the material of the solid, and wherein:
 the solid is moved in a translational manner in XY direction with respect to the LASER light source, and 
 the number of modifications per cm 2  of the solid surface, through which the LASER radiation penetrates into the solid in order to generate the modifications, wherein the maximum number of the modifications per cm 2  and according to the translational movement in XY direction is preferably determined as a function of the solid material and of the energy density of the LASER radiation, and/or 
 the modifications are generated with different patterns, in particular distances between the individual newly generated modifications, and/or with changed energy input, in particular reduced energy input, according to the translational movement in XY direction of the solid with respect to the LASER light source, and/or 
 the LASER light source is embodied as scanner, and the generation of the modifications takes place as a function of the laser scanning direction, the laser polarization direction and the crystal orientation, and/or 
 the distance between the displacements of two modifications, which are generated consecutively in modification generating direction is less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm, and/or 
 the outer limitations of modifications, which are generated consecutively in modification generating direction, are spaced apart from one another by less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm. 
 
     
     
         27 . The method according to  claim 16  further comprising the LASER radiation generating modifications, in particular crystal lattice effects, in the solid, wherein:
 the solid is moved in a translational manner with respect to the LASER light source, and 
 the number of the modifications per cm 2  of the solid surface, through which the LASER radiation penetrates into the solid in order to generate the modifications, wherein the maximum number of the modifications per cm 2  and according to the translational movement in XY direction is preferably determined as a function of the solid material and of the energy density of the LASER radiation, and/or 
 the modifications are generated with different patterns, in particular distances between the individual newly generated modifications, and/or with changed energy input, in particular reduced energy input, according to the translational movement in XY direction of the solid with respect to the LASER light source, and/or 
 the LASER light source is embodied as scanner, and the generation of the modifications takes place as a function of the laser scanning direction, the laser polarization direction and the crystal orientation, and/or 
 the distance between the displacements of two modifications, which are generated consecutively in modification generating direction is less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm, and/or 
 the outer limitations of modifications, which are generated consecutively in modification generating direction, are spaced apart from one another by less than 10000 nm, in particular less than 1000 nm, in particular less than 100 nm. 
 
     
     
         28 . The method according to  claim 16  further comprising, after cutting off the solid portion, LASER radiation from the LASER source is again applied to the remaining solid, wherein:
 the LASER radiation controls the temperature of a predefined portion of the remaining solid inside the remaining solid in a defined manner such that a detachment zone is formed, and 
 the temperature created in the predefined portion of the solid is so high that the material, which forms the predefined portion, is subjected to a predetermined material conversion. 
 
     
     
         29 . The method according to  claim 16  further comprising the thermal application of the receiving layer including a cool-down of the receiving layer to a temperature of below 20° C., in particular below 10° C. or below 0° C. or below −10° C. or below −100° C. or below −125° C. to or below the glass transition temperature of the material of the receiving layer.