Advanced optical model for the ellipsometric study of ionimplantation-caused damage depth profiles in single-crystalline silicon

摘要

Damage depth profiles have been investigated by spectroscopicellipsometry (SE) using an improved optical model for the evaluation.Damage created by ion implantation of Ar+ ions into singlecrystalline silicon was characterized using SE and Rutherfordbackscattering spectrometry (RBS). To create buried disorder, Ar+ ions with an energy of 100 keV were implanted into the samples.Ion doses of 4.65×1014 cm-2 and6.75×1014 cm-2 were used. In our opticalmodel, the damage profile is described by sublayers with thicknessesinversely proportional to the slope of the profile, in contrast to theearlier model having equal thicknesses. The thicknesses of the sublayersare automatically calculated from the four parameters of the coupledhalf-Gaussian profile, while the number of the layers are held constant.The improved fit quality and the results of measurements made by RBS andtransmission electron microscopy basically supported the optical modelof SE