Patent ID: 7125778

Claim:
A method for fabricating a self-aligning mask in a configuration, which comprises the steps of: forming, on a semiconductor substrate, a second protrusion structure with a small top surface disposed at a distance from a first protrusion structure with a larger top surface, the first and second protrusion structures having the same height and constituting webs having differently sized cross sections with a trench formed therebetween, the small top surface and the larger top surface constituting the total top surface of the configuration; covering the first protrusion structure and the second protrusion structure with a covering layer, a first area of the covering layer covering the second structure protrusion having a smaller thickness than a second area of the covering layer covering the first protrusion structure, the covering step further including: forming the covering layer with a sidewall disposed between the first protrusion structure and the second protrusion structure, the sidewall declining from the first protrusion structure towards the second protrusion structure; and forming the covering layer with a substantially constant thickness above the second protrusion structure; and removing the covering layer substantially homogeneously until the second protrusion structure being completely uncovered, and the first protrusion structure remaining completely covered by the covering layer.