Improvement of CVD SiO2 by Post Deposition Microwave Plasma Treatment

We evaluated density and chemical bonding states of the CVD SiO2 film with and without plasma treatment to clarify an effect of the plasma treatment. It was found that the chemical bonding states were homogenized by the plasma treatment from the results of X-ray photoelectron spectroscopy. In addition, an increase of the film density was also observed. These results indicate the densification of SiO2 film, suppression of bond-angle fluctuation, and decrease of impurities (e.g. Hydrogen, Nitrogen and so on) in the SiO2 film. These results can well explain the improvement of the electrical properties by the plasma treatment. Furthermore, UV-Raman measurement was performed to evaluate the modification of Si stress and crystal quality at the SiO2/Si interface.