Growth of ZnO thin films on interdigital transducer/Corning 7059 glass substrates by two-step fabrication methods for surface acoustic wave applications

ZnO films were grown on interdigital transducer (IDT)/Corning 7059 glass substrates by RF planar magnetron sputtering using two-step fabrication methods for surface acoustic wave (SAW) applications. The crystalline structure of the as-deposited ZnO films was characterized by x-ray diffraction (XRD) and x-ray rocking curve analysis. The SAW properties, including coupling coefficient and insertion loss, were evaluated and compared with the theoretical results. ZnO films deposited by the two-step fabrication method exhibited a lower insertion loss and a closer agreement between the experimental coupling coefficients and the corresponding theoretical values in comparison with films deposited by the one-step fabrication method. The results could be useful in the design of high-coupling low-loss SAW devices.