Investigation of the transition region between SiO2 layers wet grown at 700 degrees C and Si

Silicon oxide layers wet grown at 700 degrees C on silicon substrates of integrated circuit quality have been investigated by slow-positron-implantation spectroscopy and Auger electron spectroscopy. The total thickness of pure SiO2 on top of a SiO2/Si transition zone is determined by ellipsometric measurements; the positron/Auger results indicate that the transition zone extends over 15-23 nm. Its thickness decreases as the SiO2 layer is thinned by a wet-chemical process at room temperature. The results are consistent with earlier secondary-neutral mass spectroscopy measurements.