Optical properties of fluorinated silicon oxide (SiOF) films for optical waveguide in optoelectronic devices were investigated. The SiOF films are formed at 25 °C by a liquid phase deposition (LPD) technique using a supersaturated hydrofluosilicic acid (FhSiFe) aqueous solution. Two main absorption peaks corresponding to Si-O and Si-F bonds were observed at the wavenumbers of 1090 and 930 cm-1 in Fourier transform infrared (FTIR) spectrum, respectively. The LPD-SiOF films show very little content of water components such as Si-OH bonds and OH group. Although the transmittance for 600-nmthick LPD-SiOF film gradually decreased from the wavelength around 700 nm, the relative transmittances to quartz glass are over 98% in the wavelength region from 350-2500 nm. The concentration of fluorine atoms in the LPD-SiOF film was about 5%, and the calculated composition was SiOi.gsFo.is. The calculated refractive index from the polarizability for LPD-SiOF film was 1.430, and agrees very well with the measured value at the wavelength of 632.8 nm by ellipsometry. The dispersion of refractive index was evaluated and fitted to a three-term Sellmeier's dispersion equation. The zero dispersion wavelengths for the LPD-SiOF and thermally grown SiO2 films were 1.271 and 1.339 μm, respectively.
|IEEE Transactions on Instrumentation and Measurement
|Published - 1998
ASJC Scopus subject areas