Contribution of interface roughness to the infrared spectra of thermally grown silicon dioxide films

Interfacial oxide structures were studied by Infrared reflection absorption spectroscopic analysis. The longitudinal optical mode of the interfacial oxide films arose with lower frequencies and wider widths. We assumed and later verified that these changes resulted from the contribution of interfacial roughness. We therefore examined the contribution of interfacial roughness to the infrared spectra using the effective medium approximation model and via infrared spectra simulation. The experimental results explained by a model of that interface had an atomically roughness of within 1 nm and chemical structure changes effectively little fluctuation.