Initial oxidation of H-terminated Si(100) in O3 (950 ppm)/O2 and pure O2

The initial oxidation of the H-terminated Si(100) surface was studied in O-3 (950 ppm)/O-2 and molecular oxygen ambient using contact angle goniometry, mirror enhanced polarized reflection Fourier transform infrared (FTIR), and attenuated total reflection FTIR spectroscopy at low temperatures (<300°C). Mono-, di-, and tri-hydrides were removed gradually, while intermediate species such as silicon oxy-hydrides and epoxides were formed on the Si surface. During the O-3/O-2 or O-2 oxidation, H2O contact angles decreased from ∼72° (H-terminated hydrophobic surface) to a low asymptotic value (hydrophilic oxide surface) after a minimum value was achieved in the meantime. Species like suboxides appeared to be responsible for the observed minimum of the H2O contact angles. CH2I2 contact angles had high sensitivity at high H coverage on Si(100) surfaces, while H2O contact angles had high sensitivity at low H coverage. The removal of hydrides between 2000 and 2200 cm(-1) in O-3/O-2 was substantially faster and less temperature-sensitive than that in O-2. Samples processed in O-3/O-2 had H2O contact angles ∼30-5° lower than those processed in pure O2. FTIR studies suggest an ozone-related adsorption species at ∼1727 cm(-1) during the O-3 (950 ppm)/O-2 oxidation of H-terminated Si(100). (C) 2003 The Electrochemical Society.