Published online by Cambridge University Press: 22 February 2011
The effects of the heat treatment of Si covered with a thermally-grown ˜50 nm overlayer of SiO2 were probed by means of measurements of positron annihilation characteristics obtained with a variable-energy positron beam. From measurements at elevated temperature (˜500°C) it was observed that positrons implanted overlapping the SiO2/Si interface decay from a state with properties distinctively different from the state in Si and in SiO2. The nature of the annihilation characteristics indicates the presence of open volume defects.