Finite element simulation of Rayleigh surface acoustic wave in (100) AlN/(100) ZnO/diamond layered structure

Abstract:

With the rapid development of the fifth-generation (5G) wireless system, the explosive growth of transmitted data raises higher requirements for high-performance surface acoustic wave (SAW) devices as filters and duplexers. (100) AlN/(100) ZnO/diamond layered structures are theoretically simulated by finite element method (FEM) to investigate the Rayleigh SAW propagation properties, including phase velocity, electromechanical coupling coefficient K2, and temperature coefficient of frequency (TCF). Three types of layered structures with different interdigital transducers (IDTs) arrangements, which are IDTs/(100) AlN/(100) ZnO/diamond, (100) AlN/IDTs/(100) ZnO/diamond, and (100) AlN/(100) ZnO/IDTs/diamond structures, are considered in the simulations. The results show that the Sezawa mode exhibits larger K2 than the other modes. We found that the (100) AlN/IDTs/(100) ZnO/diamond structure exhibited better SAW properties, including high K2 and appropriate phase velocity.