Resonance properties of leaky surface acoustic waves and plate waves on LiTaO3 thin plate bonded to SiC-on-Si substrate

In recent years, thin-film surface acoustic wave (TF-SAW) devices have gained attention as radio frequency (RF) filters, offering enhanced performance by concentrating surface wave energy near the surface through the thinning of the piezoelectric substrate. Typically, a piezoelectric substrate is bonded to a support substrate, such as Si with an intermediate SiO2 layer, to achieve the desired thickness and facilitate handling. However, the low thermal conductivity of SiO2 raises concerns about poor heat dissipation. To address this issue, we focused on silicon carbide (SiC), which has high thermal conductivity, and proposed a composite structure in which a LiTaO3 (LT) layer is bonded to a SiC-on-Si support substrate (LT/SiC/Si). Furthermore, we introduced a plate-wave device by removing the Si support, leaving a freestanding LT/SiC membrane to excite plate waves. This paper discusses the simulation analysis and prototyping of resonators based on these two structures.