The optical properties of SiOxformed by high-dose Si ion implantation into fused silica

Abstract

Abstract SiOx layers with continuous depth profiles of the oxygen concentration are formed about 2 μ below the surface by 2 MeV Si ion implantation into fused silica. The depth distribution of the changed optical properties is revealed by high-resolution reflection and transmission profiles measured across the beveled surface of the irradiated samples. The underlying depth profiles of the refractive index and of the extinction coefficient are evaluated from reflection and transmission measurements by a method which is based on exact formulas for the light propagation within continuous depth profiles of the complex refractive index. The resulting n and k profiles are correlated with depth profiles of the oxygen concentration which are theoretically calculated for the investigated dose range (1 × 1016 to 6 × 1017 cm−2). The optical data of SiOx for x between 2 and 1.1 are presented in the wavelength range from 365 to 1000 nm. Comparison with the effective medium model proposed by Zuther for evaporated SiOx and with experimental data of evaporated layers shows the influence of bonding defects on the optical properties of ion implanted SiOx.