Proposed is an epitaxial substrate, particularly for making thin-film semiconductor chips based on III-V semiconductors, comprising a sacrificial layer that is applied to a wafer substrate and whose band gap is smaller than the band gap of the surrounding substrate, and a method of making the epitaxial substrate. Further described is a method of making a thin-film semiconductor chip, particularly an LED, wherein an epitaxial substrate is prepared, wherein at least one LED structure is grown on said epitaxial substrate and the LED structure is bonded to an acceptor substrate, and wherein the semiconductor wafer is released by at least partially destroying the sacrificial layer, and the at least one LED structure is singulated.