Wafer surface reconstruction from topdown scanning electron microscope images
In this paper, we propose and investigate several solutions to a difficult inverse problem which arises in semiconductor fabrication. The problem is to deduce a feature's vertical cross-section from two-dimensional topdown scanning electron microscopy (SEM) images of the feature surface. Our first approach is to directly map from SEM intensity waveform to line profile. We show that the direct inverse function approach to profile reconstruction is very sensitive to intensity changes and that it can therefore be used to detect variations in wafer surface patterns. The other two approaches are based on physical modeling of the interaction between the electron beam and the feature surface. Our results are illustrated with a variety of real data sets originating from industry.
semiconductor fabrication scanning electron microscopy critical dimension metrology artificial neural networks image processing