Deposition and characterization of Er⁺³-doped, Al co-doped sol-gel silica films on SOS

Abstract Up to 18 layers of crack-free Er-doped sol-gel silica films co-doped with Al were deposited on SOS (silica on silicon) by multiple spin-coating and rapid thermal processing (RTP). The properties of the films were studied using ellipsometry, FTIR (Fourier Transform Infrared) Spectroscopy, AFM (atomic force microscopy) and XRD (X-ray diffraction). The results showed that, compared with air environment, a moderate (45–50 mbar) vacuum annealing environment could remove water molecules (H2O) in the prepared film more effectively and yield smoother film surface.