Edge reflection type SAW resonators on silicon substrate using ZnO thin films

A compact SAW resonator on silicon substrate has been proposed based on complete reflection property of shear horizontal surface waves at free edges and the Love wave generation capability of ZnO film in conjunction with IDT, the proposed device was fabricated and characterized. Love waves are excited in the overlaid ZnO film on silicon substrate and vertical grooves are micromachined into silicon substrate to form free edges of the device in order to facilitate the total reflection of Love waves. The phase velocity and electromechanical coupling coefficient dispersion characteristics of various layered configurations with respect to thickness of ZnO were obtained through finite element simulations. Edge reflection type SAW resonators were designed using equivalent circuit method for fabrication process and the devices were characterized for S11 parameters. Q factor of 498.5 at resonance frequency of 261.72 MHz was achieved for ZnO/IDT/Si configured SAW resonator on silicon substrate.