Thickness-Dependent Frequency Shift in Infrared Spectral Absorbance of Silicon Oxide Film on Silicon

Abstract

The spectral dependence of the refractive index n and extinction coefficient k of chemical-vapor-deposited (CVD) silicon oxide film on silicon wafer has been determined. The results are used to calculate spectral absorbances for 0.1–2 μm thick oxide films with unchanged structure. The dependence on thickness of the position of Si-O stretching ( vM) has been investigated. The main factor influencing the frequency is the transmission factor at the air/film and film/substrate boundaries. In the limit of d → 0, vM corresponds to the maximum of the Im (ε) function.