PIEZOELECTRIC AIN FILM FOR SAW DEVICES APPLICATIONS

Polycrystalline AlN films with the c-axis oriented normal to the substrate surface, were deposited by RF reactive diode magnetron sputtering on fused quartz, silicon and sapphire. The films were characterized as to their morphology, optic and acoustic characteristics. The phase velocity dispersion curves vs. normalized film thickness were evaluated theoretically together with the electromechanical coupling coefficient for the four different interdigital transducers geometries. The theoretical results were compared with the experimental values. Results showed AlN film suitable for applications to SAW devices