Abstract:(100)AlN/(100)ZnO/diamond layered structures are theoretically simulated by finite element method (FEM) to investigate the Rayleigh surface acoustic wave (SAW) propagation properties, including phase velocity, electromechanical coupling coefficient K2, and temperature coefficient of frequency (TCF). Three types of layered structures with different 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.