Pulsed laser deposition of SrxBa1-xNb2O6/MgO bilayered films on Si wafer in waveguide farm

Strontium barium niobate (SBN) thin films were grown on Si (111) substrates coated with MgO buffer by the pulsed laser deposition (PLD) technique. The thickness of SBN and MgO films were of the order of 1200 nm and 840 nm respectively. X-ray energy dispersive spectrometry (XREDS) showed that SBN films have stoichiometric composition identical to the target material, and no Si diffusion into the SBN film was found. X-ray diffraction (XRD) theta-2 theta scans indicated that MgO films were highly (111) textured, but the SBN films were polycrystalline without preferential orientation. The surface of the SBN film was smooth, dense and crack-free, and no large droplets were observed when studied under a scanning electron microscope (SEM). A favourable optical waveguiding properly of the bilayered films was demonstrated by a prism coupler method.