Growth and modeling of cw-UV induced oxidation of silicon

Abstract

A report on the use of a low pressure Hg discharge lamp to grow 100 Å SiO₂ layers on Si at 550 °C. The induced reaction rate is more than 12 times that for thermal oxidation of Si at 612 °C, indicating that the growth mechanism is photonically controlled. We tentatively suggest that the induced oxidation is based on space‐charge controlled drift of ionic oxygen species created in the SiO₂ by charge photoinjected from the Si. Simple modeling predicts a limiting thickness for film growth that is confirmed by experimental evidence. An activation energy of 0.56 eV extracted from the data compares with values of 0.14 – 0.7 eV previously reported for oxidation of silicon by O or O⁻ species.