Method for producing etch mask, method for etching structure in substrate, use of group 4 element layer and structure for producing mask

The present invention relates to a method (100) for preparing an etch mask, wherein the method (100) comprises: a step (105) of providing a substrate; a step (110) of applying a metal layer, wherein the metal layer comprises or is formed from at least one transition metal and/or aluminum; a step (115) of applying a mask layer; a step (120) of structuring the mask layer, wherein the metal layer is exposed in at least one processing region; a step (125) of coating the substrate with a Group 4 element layer at least partially comprising a Group 4 element, wherein an interdiffusion region between the transition metal or aluminum and the Group 4 element is formed in the treatment region at the interface between the metal layer and the Group 4 element layer; a step (130) of removing the mask layer; and a step (135) of selectively etching the metal layer, in which the substrate is exposed in at least one etched region other than the processing region, and the metal layer is at least partially maintained in the proce