THERMAL-DESORPTION STUDIES OF SILICON DIOXIDE DEPOSITED BY ATMOSPHERIC-PRESSURE CHEMICAL-VAPOR-DEPOSITION USING TETRAETHYLORTHOSILICATE AND OZONE

The relationship between the structural properties of TEOS/O3-NSG and deposition conditions is studied with thermal desorption spectroscopy. The principal thermally desorbed species, except for O2, are divided into two categories: H2O-related species and ethoxyl-group-related species. Most part of the H2O-related species, such as H2O, OH, O and H-2, are generated from silanol groups rather than actual water in the oxide. In contrast with O-atom desorption, O2-molecule desorption is not synchronized with H2O desorption. It is likely that desorbed O2 has its origin in ozone included in the source gas. The ethoxyl-group-related species, including OC2H5, OC2H4, C2H5, and C2H4, arise from components that have been incorporated into the oxide atomic network due to the incompleteness of TEOS decomposition. The dependence of thermal desorption spectra on source-gas composition and deposition temperature is described.