Surface acoustic waves in c-axis inclined ZnO films

Surface acoustic wave propagation in c-axis inclined ZnO films has been studied in order to assess the possibility of using films of this kind in shear horizontal (SH) wave devices. The authors calculate the velocity dispersion and the electromechanical coupling coefficient for generalized Rayleigh and Love modes propagating along inclined-axis ZnO films on fused quartz and silicon substrates. The analysis has been done for different values of the inclination angle and of the ratio between film thickness and acoustic wavelength. ZnO films with the c-axis oriented 30° to the surface normal were deposited by reactive RF magnetron sputtering on fused quartz. They were successfully used for the generation and detection of Love modes. Measurements of phase velocity of surface modes by ultrasonic and Brillouin scattering techniques permitted the elastic characterization of the films.