Raman Microprobe Analysis of Simox Structures Implanted With Screen Oxide

Abstract

ABSTRACTThe analysis of SIMOX structures obtained by doing the implantation with different thicknesses of thermal oxide (screen oxide) has been perfomed by Raman scattering, and the results have been correlated with those previously obtained by TEM. The use of a microRaman system on low angle bevelled sample has allowed to directly observe the different regions in the structures, corroborating the structural differences observed by TEM as a function of the screen oxide thickness. For as implanted structures, strong non homogeneous strain and disorder effects are observed in the top Si layers. After the High Temperature Anneal (HTA) process, crystalline quality of the structures is improved. The analysis of the spectra obtained at different excitation powers points out the dependence of the thermal effects of the spectra on the structural features of the scattering volume, as the dislocation density in the annealed layers. This dependence allows the assesment of the crystalline quality of these structures to be made.