Edge detection at height profiles with nano resolution

The advances at the semiconductor fabrication and the increasing miniaturization entail a need for 3D nano coordinate measurements. The presented paper describes a novel method to derive lateral measuring information from height profiles with nanometer resolution. The method is also applicable when the batwing effect occurs. Thus, it can be applied also at structures with a height smaller than the coherence length of the light source used. Edge detection algorithms well known from optical precision measurements are used to estimate the location of the edge along the scan line of the focus sensor. The presented work is the result of the interdisciplinary research within the collaborative research centre SFB622.