We report the formation of high-quality silicon-on-insulator materials using separation-by-implantation-of-oxygen (SIMOX) technology, with doses ranging from 1.8 to 13.5×1017 cm-2 at acceleration energies of 45–160 keV, and subsequently annealed at a high temperature of over 1300 °C in an oxygen and argon atmosphere for 5 h. The microstructure evolution of SIMOX wafers was characterized by Rutherford backscattering spectroscopy, transmission electron microscopy, modified enhanced Secco, Cu plating, and spectroscopic ellipsometry. The study reveals a series of good matches of dose–energy combination at acceleration energies of 45–160 keV with doses of 1.8–5.5×1017 cm-2, in which the SIMOX wafers have good crystallinity of the top silicon, a sharp Si/SiO2 interface, and a high-integrity buried oxide layer with a low pinhole density and few detectable silicon islands. Furthermore, the higher the oxygen dose, the higher the implanted energy required for the formation of a Si-island-free buried oxide layer. The mechanism of an appropriate dose–energy match is discussed. © 2003 American Vacuum Society.