Disclosed is a method for separating a substrate (1) along a separation pattern (4), in which method a substrate (1) is provided and an auxiliary layer (3) is applied to the substrate, said layer covering the substrate at least along the separation pattern. The substrate comprising the auxiliary layer is irradiated, such that the material of the auxiliary layer penetrates the substrate along the separation pattern in the form of an impurity. The substrate is broken along the separation pattern. A semiconductor chip (15) is also disclosed.