Abstract
It is demonstrated that infrared absorption spectroscopy of the transverse optic and longitudinal optic vibrational modes of the asymmetric bridging oxygen stretch in amorphous SiO2 may be used to conveniently estimate film thickness in sandwiched structures. Measurements have been made on the SiO2 film formed at the substrate/dielectric interface during deposition of Ta2O5 on Si substrates and the evolution of its thickness during subsequent annealing. The accuracy of the film thickness determined is compared with electron microscopy observations.