Simulation of characteristics of a SiO(2)/c-axis-oriented LiNbO(3)/diamond surface acoustic wave

High-frequency surface acoustic wave (SAW) devices based on diamond that have been realized to date utilize c-axis-oriented ZnO as the piezoelectric thin film. This material, with SiO(2) overlay, shows excellent characteristics of a high phase velocity of over 10,000 m/s and a zero temperature coefficient, and it has been successfully applied to high-frequency SAW filters and resonators. To expand on materials used on diamond, the theoretical calculation has been carried out for LiNbO(3)/diamond, and a high electromechanical coupling coefficient up to 9.0% is expected. In this work, the characteristics of SiO(2)/LiNbO(3)/diamond were studied by computer simulation, emphasizing a zero temperature coefficient with a high coupling coefficient. Calculations are carried out for the phase velocity, the electromechanical coupling coefficient, and the temperature coefficient of the Rayleigh wave and its higher mode Sezawa wave. As a result, SiO(2)/IDT/LiNbO(3)/diamond is found to offer a zero temperature coefficient with a very high coupling coefficient up to 10.1% in conjunction with a high phase velocity of 12,100 m/s.