Redistribution Process of Oxygen Atoms in Separation-by-Implanted-Oxygen (SIMOX) Substrates

To form separation-by-implanted-oxygen (SIMOX) substrates, oxygen ions were implanted into the conventional (100) single-crystal silicon substrates at 80 keV to a dose of 1.0×1018 cm-2, maintaining the substrate temperature at around 520°C. Before and after post implantation annealing at 650–1280°C for 2 h, we examined silicon-on-insulator (SOI) structures of the SIMOX substrates using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared absorption spectroscopy (FTIR), cross-sectional transmission electron microscopy (XTEM), and Rutherford backscattering spectroscopy (RBS). On the basis of the experimental results of the XPS measurements (depth profiles of oxygen concentration and Si2p spectrum at around the binding energy of 99–105 eV) and the FTIR measurements (the peak position and the full width at half-maximum of the absorption peak associated with the Si–O stretching mode at around 1080 cm-1), together with XTEM images and RBS spectra, we clarified that inward migration of the implanted oxygen atoms is one of the primary processes for the formation of the SOI structure, and discussed the redistribution process of the implanted oxygen atoms as a function of the annealing temperature.