A method which makes it possible to define in a patterning layer openings having a first dimension that is substantially less than the feature size that can be obtained lithographically includes applying a sacrificial layer made of a material that is different from that of the patterning layer in a predetermined layer thickness on the patterning layer. Afterward, a photoresist layer is applied on the surface of the sacrificial layer, and an opening having a second dimension is defined lithographically in the photoresist layer. Afterward, an etching angle is set in a manner dependent on the layer thickness of the sacrificial layer and also the first and second dimensions, and the sacrificial layer is etched at the etching angle set. Afterward, the patterning layer is etched, the sacrificial layer is removed and a filling material is introduced into the opening produced in the patterning layer.