Atmospheric-pressure chemical Vapor deposition of silicon dioxide films, using tetraethoxysilane and ozone sources, can produce a flowing-like step coverage on a patterned substrate. We evaluate the characteristics of silicon dioxide films deposited on a patterned substrate and compare them with those on a flat surface. Thermal desorption spectroscopy detects synchronous mle = 48 and mle = 64 fragments only in silicon dioxide films deposited on patterned substrate. The spectral change for the mle = 32 fragment is also detected. The contaminants, which desorb the parent species of mle = 48 and mle = 64 fragments during thermal desorption spectrometry, are localized in the bottom corner of the steps on patterned substrates. In Fourier transform infrared spectra of the film on patterned substrates, the peak attributed to the Si-O stretching vibration mode shifts and spreads to lower wave numbers.