Infrared absorption study of rapid thermal oxidation and in situ steam generation of thin $SiO2$ films by gradient etching preparation

$SiO2$ thin films prepared by rapid thermal oxidation (RTO) and in situ steam generation (ISSG) were characterized by infrared spectroscopy (IR) with gradient etching preparation and grazing incidence x-ray reflectometry. The IR spectra of the RTO films show a lower wave number shift as the film thickness decreases. On the other hand, the IR spectra of the ISSG film produced by the addition of 5% hydrogen did not show such large peak shifts. This means that the 5% hydrogen ISSG film has a very low concentration of lower wave number components that exhibit Si–O stretching mode. These are responsible for defect structures including dangling bonds and/or oxygen deficient defects near the $SiO2/Si$ interface.