Characteristics of one-port surface acoustic wave resonator fabricated on ZnO/6H-SiC layered structure

Abstract

Characteristics of one-port surface acoustic wave (SAW) resonators fabricated on ZnO/6H-SiC layered structure were investigated experimentally and theoretically. Phase velocities (Vp), electromechanical coupling coefficients (K2), quality factors (Q), and temperature coefficients of frequency (TCF) of Rayleigh wave (0th mode) and first- and second-order Sezawa wave (1st and 2nd modes, respectively) for different piezoelectric film thickness-to-wavelength (hZnO/λ) ratios were systematically studied. Results demonstrated that one-port SAW resonators fabricated on the ZnO/6H-SiC layered structure were promising for high-frequency SAW applications with moderate K2 and TCF values. A high K2 of 2.44% associated with a Vp of 5182 m s−1 and a TCF of −41.8 ppm/°C was achieved at hZnO/λ = 0.41 in the 1st mode, while a large Vp of 7210 m s−1 with a K2 of 0.19% and a TCF of −36.4 ppm/°C was obtained for hZnO/λ = 0.31 in the 2nd mode. Besides, most of the parameters were reported for the first time and will be helpful for the future design and optimization of SAW devices fabricated on ZnO/6H-SiC layered structures.