Analysis of the Effect of Sio2 Film on the Characteristics of Rayleigh Wave in Zno/Sic Structure

The influence of SiO2 film on the phase velocity and the electromechanical coupling coefficient of ZnO/SiC structure was analyzed by finite element method. The results show that the middle SiO2 film layer reduces the phase velocity of Rayleigh wave and significantly increases the electromechanical coupling coefficient. When the top SiO2 film layer thickness is larger than the ZnO film thickness, the Rayleigh wave phase velocity increases. Otherwise, the Rayleigh wave phase velocity decreases. The electromechanical coupling coefficient increases first and then decreases. These conclusions can guide the development of surface acoustic wave devices with high phase velocity and high electromechanical coupling coefficient.