Silica film has been produced at room temperature by a single precursor process of photolitic chemical vapor deposition using a newly developed Xe excimer lamp. Tetraethoxyorthosilicate (TEOS) has been used as a raw material. Transparent thin film of SiO2was obtained on single crystalline Al2O3substrates and its properties were evaluated by means of the reflection Fourier transformation‐infrared spectroscopy, the scanning electron microscopy, and ultraviolet‐visible spectrometry. Consequently, it was found that the main component of the film was SiO2and very small amounts of residual organic materials were contained. It was also found that the film was very dense and the refractive indices were only 1.7% smaller than that of bulk silica glass. ©1996 American Institute of Physics.