Methods for modifying substrates depending on the crystal lattice dislocation density

Abstract

A method comprising: providing a semiconductor body with a generation plane (4) and crystal lattice planes (6) intersecting the generation plane (4) at intersection lines (10); generating modifications (9) in the semiconductor body by multiphoton excitation, wherein the modifications (9) are spaced apart and alter a physical property of the semiconductor body to form subcritical cracks (12) in the generation plane (4); and separating a solid layer (2) from the semiconductor body by connecting the subcritical cracks (12) in the generation plane (4), wherein the generation of the modifications (9) in the semiconductor body by multiphoton excitation comprises: i) using a uniform polarization to form a first group of modifications (9) oriented in a first direction;and using a second polarization different from the first polarization to form a second group of modifications (9) oriented in a second direction different from the first, or ii) setting a polarization to form a group of modifications (9) such that the orientations of the modifications in the group differ from one another, or iii) setting a polarization for two or more groups of modifications (9) such that the modifications (9) of at least two of the groups have an orientation inclined to the lines of intersection (10).

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