Twofold SiOx Films Deposited by HFCVD: Its Optical, Compositional and Electrical Properties

Twofold non-stoichiometric silicon oxide (SiOx) films before and after of a thermal annealing are characterized by different techniques. The twofold SiOx films are obtained by hot filament chemical vapor deposition technique in the range of temperatures from 900 °C to 1150 °C. An important result is the optical energy band gap, which decreases as the growth temperature (Tg) increases from 2.15 to 1.8 eV. The absorption and emission properties are correlated with quantum effects in Si-nc and defects.The twofold SiOx films exhibit compositional changes with the variation of Tg and a restructuration (phase separation) take place with the thermal annealing.