Some Properties of SiO2 Films Deposited by the Reaction of SiH4 with Water Vapor

SiO2 films were deposited on the n-type Si substrates by the reaction of SiH4 with water vapor in the temperature range 900°∼1200°C. The refractive index and etching rate with HF solution of SiO2 films prepared at 900°C were strongly dependent on the molar ratio of water vapor to SiH4, but no shifts of the 9 micron absorption peaks by the stretching vibration of Si-O-Si bonds were observed among the films prepared at different molar ratios and at 900°C. These results indicate that Si atoms are included in these SiO4 films. A capacitance-voltage hysteresis of the metal-oxide-silicon structure was observed and attributed to a phenomenon caused by the ionization of Si atoms in the SiO4 films.