Multiple total internal reflection Fourier transform infrared spectroscopy is used to detect combinational phonon bands of SiO2 at 1645, 1852, and 2000cm-1 in thin films produced by plasma enhanced chemical vapor deposition. The isotopic shifts of these bands in films deposited from SiH4/18O2 mixtures proved that combinations of SiO2 phonons give rise to the additional absorption peaks. Detection of these combinative phonon bands enables one to use Si multiple total internal reflection crystals for studying Si-O phonon absorptions in SiO2 films on Si. In principle, films as thin as a few angstroms can be detected using the infrared absorption by the combinational bands.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)