Thin film lithium niobate on sapphire for SAW applications

Deposition of LiNbO3 thin films on R-cut (<01(1)over bar 2>) sapphire by rf magnetron sputtering has been systematically investigated and repeatable epitaxial relationships between LiNbO3 thin film and sapphire substrate were observed. As a result, the effect of sputtering parameters on deposition of LiNbO3 thin films was determined. Optimal conditions for deposition of high quality (<11(2)over bar 0>), (<01(1)over bar 2>) and (<10(1)over bar 0>) LiNbO3 thin films were found. A filter was successfully fabricated by forming interdigital transducers (IDT) on the surface of a (<10(1)over bar 0>) LiNbO3 thin film on (<01(1)over bar 2>) sapphire. The frequency response curve was measured, and the results are compared with a theoretical model.