PZT based multilayer surface acoustic wave device for high frequency applications

This paper presents a study on the integration of PZT thin film on SiO2/Si substrate, which offers a great deal of potential in high frequency applications. A finite element method (FEM) simulation analysis of the proposed PZT/SiO2/Si multilayer surface acoustic wave device is performed, and two propagation modes are studied i.e. the Rayleigh and Sezawa wave mode. The proposed structure is optimized by PZT (tPZT) and SiO2 (tSiO2) layers thicknesses. The Rayleigh mode is optimized with k2=6.27 at tPZT/λ=0.4 and tSiO2/λ=0.025 and the Sezawa mode with k2 =13.13 at tPZT/λ =0.2 and tSiO2/λ=0.025. The temperature coefficient of frequency of the Sezawa mode is 2.7 times lower than that of the Rayleigh mode. Which makes it a more suitable choice for temperature stable high frequency and high k2 SAW devices. © 2019 IEEE.