Preparation and Optical Waveguide Properties of LiNbO₃ Thin Films by RF Magnetron Sputtering

C -axis-oriented LiNbO 3 films were successfully obtained on ZnO/SiO 2 /Si, ZnO/glass and Pt/SiO 2 /Si substrates at substrate temperatures higher than 450°C by RF magnetron sputtering. LiNbO 3 films were also grown epitaxially on α-Al 2 O 3 (001), (012) and (110) and LiTaO 3 (110) substrates at substrate temperatures higher than 650°C. The minimum optical propagation loss of the films was 6.47 dB/cm (TE 0 mode) for the LiNbO 3 film on LiTaO 3 . An improvement in the optical propagation loss after annealing treatment was observed.