Patent ID: 7897423
Filing Date: 2011-03-01
Classification: H01L

Abstract:
1. A method for micropatterning a radiation-emitting surface of a semiconductor layer sequence for a thin-film light-emitting diode chip, comprising the steps of: (a) growing the semiconductor layer sequence on a substrate; (b) forming or applying a mirror layer on the semiconductor layer sequence, which reflects back into the semiconductor layer sequence at least part of a radiation that is generated in the semiconductor layer sequence during operation thereof; (c) separating the semiconductor layer sequence from the substrate with a lift-off method, in which a separation zone in the semiconductor layer sequence is at least partly decomposed such that anisotropic residues of a constituent of the separation zone remain at a separation surface of the semiconductor layer sequence and the substrate is separated from said semiconductor layer sequence, the anisotropic residues being formed on the semiconductor sequence as a layer having a varying layer thickness; and (d) etching the separation surface—provided with the anisotropic residues—of the semiconductor layer sequence with a dry etching method, a gaseous etchant or a wet-chemical etchant, wherein the anisotropic residues are temporarily used as an etching mask, wherein the etching results in roughening the separation surface wherein the separation zone that is decomposed in step (c) contains AlGaN, an Al content of the AlGaN lies between approximately 1% and approximately 10%, and Al of said AlGaN is sintered into the semiconductor layer sequence.