In this paper we describe the analysis by Raman scattering and photoluminescence spectroscopy of silicon-on-insulator (SOI) structures obtained by sequential implantation and annealing (SIA). TEM observations have allowed correlation of the tensile strain observed from the Raman spectra obtained with excitation wavelengths higher than 488 nm and the D bands from the photoluminescence spectra to the presence of a region with precipitates and dislocations close to the buried oxide. Likewise, the comparison between the Raman spectra obtained with lower wavelength (457.9 nm) from SIA samples and from equivalent ones obtained by a single implantation and anneal, has corroborated the higher quality of the surface silicon layer from the SIA structure.