Influence of substrate temperature on the growth and optical waveguide properties of oriented LiNbO 3 thin films

Abstract

C-axis-oriented LiNbO 3 thin films have been deposited on SiO 2/Si substrates by pulsed laser deposition (PLD). The amorphous SiO 2 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 LiNbO 3 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 LiNbO 3 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.