CHARACTERIZATION OF SILICON-ON-INSULATOR MULTILAYERS USING EX-SITU SPECTROSCOPIC ELLIPSOMETRY AND IN-SITU MONOCHROMATIC ELLIPSOMETRY DURINGPLASMA-ETCHING

This is a characterization study on separation by implanted oxygen str uctures designed to extract maximum information on the thicknesses of the layers produced by implantation, and more importantly on the quali ty of the top Si layer after annealing. The objective was to do this n on-destructively using spectroscopic ellipsometry (SE). In order to co nfirm and extend the analytical power of SE, the measurements have bee n coupled with in situ studies using monochromatic ellipsometry during plasma etching of selected samples. This has enabled some of the rema ining uncertainties in layer refractive indices in the SE-derived mode ls to be resolved and has shown that some of the reference data, parti cularly for the buried oxide, need to be modified.