PZT Based Multilayer Surface Acoustic Wave Device for High Frequency Applications

This paper presents a study on the integration of PZT thin film on SiO 2 /Si substrate, which offers a great deal of potential in high frequency applications. A finite element method (FEM) simulation analysis of the proposed PZT/SiO 2 /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 (t PZT ) and SiO 2 (t SiO2 ) layers thicknesses. The Rayleigh mode is optimized with k2=6.27% at t PZT /λ=0.4 and t SiO2 /λ=0.025 and the Sezawa mode with k2 =13.13% at t PZT /λ =0.2 and t SiO2 /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.