Physical Behavior of Fluorine Atoms in the Fabricated Transparent SiO2 Thin Film at Room Temperature

Abstract

AbstractThis paper describe the growth of a transparent SiO2 thin film performed by using Xe2• excimer lamp at room temperature. In this study, NF., and O2 mixture gases was employed as a reaction gas. A silicon substrate was placed in a reaction chamber, which was filled with NF3 and O2 mixture gases. The mixture gases were exposed to the Xe2• excimer lamplight, and SiF4 and NO2 gases were produced by photochemical reaction. Subsequently SiF4 adsorbed onto the Si substrate. SiO2 was formed by oxidation reaction between SiF4 and NO2. These processes occur spontaneously, and SiO2 film is grown. The refractive index of fabrication SiO2 thin film is 1.32. By annealing at 200°C, the refractive index of this filn was increased to 1.44. Further increase in the annealing temperature, resulted in a higher refractive index and lower density of fluorine atoms.