Abstract
Thin films have been deposited by photo assisted chemical vapor deposition with Xe2 excimer lamp as a vacuum UV (VUV) source using Tetraethoxysilane (TEOS) as an organic silicon source. A chemical stability of films exposed to in atmospheric condition was measured by means of Fourier transform infrared spectroscopy (FTIR) during 4 weeks in the every week. It was shown that the film deposited from only TEOS at room temperature has unstable chemical structure in atmospheric condition. The FT-IR result indicated that C-H peak was decreased and OH peak was increased after 4 weeks. The results on films deposited from TEOS/O2 mixture gas showed that the film included large amount of OH, as result from oxidizing CH groups. Ellipsometric analysis data on the films prepared from only TEOS indicated that refractive index was increasing and film thickness was decreasing during 4 weeks. Therefore experimental results have shown that the unstable film contained unstable CH groups. Finally the film deposited from only TEOS and TEOS/O2 at room temperature was irradiated Xe2excimer light. It was found that the VUV irradiation was effective in removing CH groups from ethoxysiloxane and decreasing OH bond in the film.
