The use of spectroscopic ellipsometry to predict the radiation response of SIMOX

We have studied SIMOX (Separation by Implantation of Oxygen) material using spectroscopic ellipsometry to determine the structure of the buried oxide and C-V measurements to determine the radiation response of the buried oxide. Our ellipsometric measurements indicate that the buried oxide is best described as a layer of stoichiometric SiO/sub 2/ which is more dense than bulk vitreous (v-) SiO/sub 2/. We find that the radiation response of the buried oxide is determined primarily by its density. We also find that small variations in the conditions used to prepare the SIMOX wafer can significantly affect the oxide density and its radiation response. The density of the buried oxide is also found to affect how it etches.<>