Amorphous SiO2 films grown by both thermal oxidation and plasma chemical vapor deposition (CVD) in a tetraethylorthosilicate and O2 atmosphere were studied using variable-energy positron annihilation spectroscopy and infrared (IR) spectroscopy. For thermally grown SiO2 layers with growth temperatures of over 1000 °C it was found that the measured Doppler broadening parameter was identical for both wet and dry growth atmospheres. The measured Doppler broadening parameter in the case of SiO2 prepared by plasma CVD was found to be strongly influenced by the substrate temperature during deposition. For a substrate growth temperature of 600 °C, the data are essentially identical to those of the thermally grown oxide layers. IR analysis revealed that the concentration of Si-OH in the SiO2 layer is affected by the substrate temperature during growth. The level of the Doppler broadening parameter in the SiO2 film exhibited changes that can be correlated with this Si-OH concentration. We thus show that the concentration of Si-OH in amorphous SiO2 film is a factor that may affect the Doppler broadening parameter.
ASJC Scopus subject areas
- General Physics and Astronomy