Characterization of LiNbO₃ thin films grown on Al₂O₃ by RF sputtering

Abstract

We describe our work on LiNbO₃ thin films grown on Al₂O₃-c by rf sputtering. X-ray diffraction shows that we grow single phase, epitaxial films in which the lithium content can be varied. Optical measurements and surface morphology characterization show that the optical loss increases with the surface roughness and that the presence of large crystalline outgrowths is a limiting factor for low loss waveguides.