A method of etching a layer arrangement

A method for etching a layer assembly which includes an intermediate layer (120) between an etch layer (110) and a stop layer (130), said method comprising the steps of: Etching the etch layer (110) using a first etchant, wherein the first etchant comprises a first etch selectivity with respect to the etch layer (110) and the intermediate layer (120); and Etching the intermediate layer (120) using a second etchant wherein the second etchant has a second etch selectivity with respect to the intermediate layer (120) and the stop layer (130), wherein the second etchant different than the first etchant, wherein the first etch selectivity, a ratio of at least 5: 1, and wherein the second etch selectivity, a ratio of at least 5: 1, wherein said stop layer (130) comprises a stop layer thickness and is carried out the step of etching the intermediate layer (120) such that the stop layer (130) is opened to a depth, wherein the depth comprises less than 50% of the stop layer thickness, ...