S0-like SAW mode resonator based on LiTaO₃/SiO₂/SiC platform

Abstract This paper studied the basic properties of the S 0 -like SAW mode on the Al/LiTaO 3 /SiO 2 /SiC structure for its implementation to the resonator. First, it is shown that this configuration offers a large electromechanical coupling factor ( k eff 2 ) when the propagation direction and the SiO 2 thickness are chosen properly. In addition, the SiO 2 layer provides temperature compensation. The impact of the electrode material and thickness is also discussed. Then, the transverse mode suppression is discussed. The “mixed piston” design, “dielectric strips” design, and the combination of “hammer-head” and “dielectric strips” designs are chosen for the discussion. The results indicated that both the “mixed piston” and “dielectric strips” designs can suppress transverse mode resonances effectively. However, the Bode Q degradation occurs near the main resonance when the piston layer thickness is large. Although the combination of “hammer-head” and “dielectric strips” designs offers good transverse mode suppression, another resonance peak newly appears below the main resonance.