Surface acoustic wave resonators based on (002)AlN/Pt/diamond/silicon layered structure

•AlN/Pt/diamond/Si structure is presented for surface acoustic wave (SAW) devices.•Higher coupling efficient than traditional structure is obtained experimentally.•SAW resonators with working frequencies larger than 1 GHz are realized.

Performance of surface acoustic wave (SAW) resonators based on (002)AlN/Pt/diamond/silicon layered structure is demonstrated. Three resonators with different wavelengths and center frequencies in the GHz range are designed and constructed without using submicron device fabrication processes, due to the high acoustic velocity of the layered structure. The enhanced performance of the SAW resonator by introducing a thin metal layer between the diamond and AlN layers is demonstrated theoretically and experimentally. Dependence of the SAW propagation characteristics on the normalized AlN film thickness is determined and the experimental results are in good agreement with theoretical predictions. In particular, for the 1st wave mode, a very high SAW velocity of 13,656 m/s and an electromechanical coupling coefficient of 0.37% are obtained. These results demonstrate that the (002)AlN/Pt/diamond/silicon layered structure is very promising for high-frequency SAW device applications.