Method for preparing and/or performing the separation of a substrate element and substrate sub-element

A method for preparing and/or performing the separation of a substrate element into at least two substrate sub-elements along a separation face, comprising the steps of:

• providing the substrate element, wherein the substrate element comprises a substrate body, and wherein the substrate body comprises a substrate material;
• and
• controlling a line focus within the substrate body so that the substrate material of the substrate body is at least locally removed and/or displaced along the separation face at least section-wise,
• wherein the controlling comprises successively generating the line focus within different effective areas in the substrate element so that the substrate material within the effective areas is removed and/or displaced, and wherein the effective areas extend in the substrate to form an at least section-wise curved volume;
• wherein the line focus represents a focus of a light beam;
• wherein the light beam is formed at least in the area of the line focus in the form of a light beam with an asymmetrical beam supply;
• wherein the asymmetrical beam supply supplies energy asymmetrically so that the centroid-of-area of the energy distribution lies in at least one plane perpendicular to the plane in which the beam propagation occurs in the area of the previously unmodified substrate material;
• and
• wherein partial beams of the light beam are only incident from directions that do not propagate through areas of the substrate body from which substrate material has already been removed and/or displaced and/or into which substrate material has been compressed.