Influence of substrate temperature on the growth and optical waveguide properties of oriented LiNbO3 thin films

C-axis-oriented LiNbO3 thin films have been deposited on SiO2/Si substrates by pulsed laser deposition (PLD). The amorphous SiO2 buffer layer was formed on Si (1 0 0) wafer by thermal oxidation method. Significant influences of the substrate temperature on orientation, crystallization, morphology and optical properties of LiNbO3 films are discussed. The crystalline orientation could be varied from (0 0 6) to (0 1 2) orientation by increasing growth temperature. Completely c-axis-oriented LiNbO3 film grown at 600 °C with surface roughness of 4.3 nm could be achieved without the aid of external electric field or any other buffer layers. Optical propagation losses were as low as 1.14 dB/cm at a wavelength of 632.8 nm.