An experimental study on the ZnO/sapphire layered surface acoustic wave device

In this study, ZnO thin films with different thicknesses were deposited on C-plane sapphire substrates by radio-frequency magnetron sputtering. Properties of interdigital transducer/ZnO/sapphire layered surface acoustic wave device including surface wave velocity, electromechanical coupling coefficient, and propagatiion loss were measured and discussed. Combining the effective permittivity approach and the coupling-of-modes (COM) model, the dispersion characteristics and frequency responses of the ZnO/sapphire layered structure were simulated. By substituting the measured parameters into the COM model, the simulated frequency response has shown good agreement with the experimental results.