RAMAN MICROSTRUCTURAL ANALYSIS OF SILICON-ON-INSULATOR FORMED BY HIGH-DOSE OXYGEN-ION IMPLANTATION - AS-IMPLANTED STRUCTURES

A microstructural analysis of silicon-on-insulator samples obtained by high dose oxygen ion implantation was performed by Raman scattering. The samples analyzed were obtained under different conditions thus lea ding to different concentrations of defects in the top Si layer. The s amples were implanted with the surface covered with SiO2 capping layer s of different thicknesses. The spectra measured from the as-implanted samples were fitted to a correlation length model taking into account the possible presence of stress effects in the spectra. This allowed quantification of both disorder effects, which are determined by struc tural defects, and residual stress in the top Si layer before annealin g. These data were correlated to the density of dislocations remaining in the layer after annealing. The analysis performed corroborates the existence of two mechanisms that generate defects in the top Si layer that are related to surface conditions during implantation and the pr oximity of the top Si/buried oxide layer interface to the surface befo re annealing. (C) 1997 American Institute of Physics.