An improved method of etching a structure and a structure etched by the method is disclosed. The bottom side of a leadframe of an IC-package is an example of a structure, which advantageously may be etched with the disclosed method. The method includes the steps of providing an etch mask to the substrate to be etched. The etch mask comprising at least two sub-mask: a first sub-mask covering the area which substantially should remain after the etching process, and a second sub-mask covering an area to be removed in the etching process. The second sub-mask is a sacrificial mask in the form of a grid. The presence of the second sub-mask increases the etching speed in the area covered by it.