Low-Temperature Oxidation of Silicon in Dry O₂ Ambient by UV-Irradiation

Abstract

The mechanism of thermal oxidation of silicon in dry O 2 ambient with UV-irradiation has been discussed. The dependence of SiO 2 thickness on oxidation time follows the model proposed by Cabrera and Mott for relatively short oxidation time. Such dependence follows the model by Deal and Grove for longer time. The main oxidizing species is ozone (O 3 ) or some other reactive species generated from O 3 at lower temperatures and this gradually changes to O 2 with an increase in temperature. The SiO 2 film formed at 500°C for 1 h by the present technique has a similar quality to that of SiO 2 formed at high temperatures in dry O 2 ambient, as evaluated from Fourier Transform-Infrared (FT-IR), Auger Electron Spectroscopy (AES) and Capacitance-Voltage (C-V) characteristics.