PREPARATION AND CHARACTERIZATION OF ND3-DOPED SILICA SOL-GEL COATINGSBY RUTHERFORD BACKSCATTERING SPECTROSCOPY AND SPECTROSCOPIC ELLIPSOMETRY( AND ER3+)

Neodymium-or erbium-doped silica films are deposited on single crystal silicon substrates using a sol-gel process and a spin-coating techniq ue. These glasses are doped with neodymium or erbium in various Nd/Si or Er/Si atomic ratios up to 8% using neodymium nitrate or erbium nitr ate as precursor. A preparation method of such films is described. Fil m rare earth concentration measured by Rutherford Backscattering Spect roscopy (RBS) is the same as in the initial liquid solution. Film thic kness and refractive index are obtained by variable angle spectroscopi c ellipsometry. We have shown that both RBS analysis and spectroscopic ellipsometry are powerful tools to control rare earth doping level an d optical properties of the silica films.