Highly concentrated (>93 vol%) ozone (O3) gas was used to oxidize silicon for obtaining high-quality SiO2 film at low temperature. Compared to O2 oxidation, more than 500°C lower temperature oxidation (i.e., from 830 to 330°C) has been enabled for achieving the same SiO2 growth rate. A 6 nm SiO2 film, for example, could be grown at 600°C within 3 min at 900 Pa O3 atmosphere. The temperature dependence of the oxidation rate is relatively low, giving an activation energy for the parabolic rate constant of 0.32 eV. Furthermore, a 400°C grown SiO2 film was found to have satisfactory electrical properties with a small interface trap density (5×1010cm-2/eV) and large breakdown field (14 MV/cm).
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