A method for forming an etch-stop layer and a resulting structure fabricated therefrom. The equipment includesat least one screw element adapted to be screwed into the ground; andat least one box-like body, mechanically fixed to the screw element. The transporting device comprises an articulated transporting frame, of which the transporting rails can be moved in opposite directions to one another. One embodiment is a target with an inner portion and an outer portion.