Three dimensional finite element modeling and simulation of quasi-shear mode resonator based on c-axis-titled ZnO film

Three dimensional finite element model for solidly mounted film bulk acoustic resonator (SMFBAR) devices with 23° c-axis-tilted ZnO film is developed and simulated using CoventorWare¿. Electromechanical coupling coefficient for 23° c-axis-tilted ZnO film calculated as high as 19% in quasi-shear mode. The particle vibration of the device at resonant frequency was measured in both quasi-shear and quasi-longitudinal modes. The impedance characteristic of the device was also analyzed using Mason´s transmission line model. As device was operated in water medium the quality factor of 136 with effective electromechanical coupling of 3.61% was obtained for in quasi-longitudinal mode while the quality factor of 283 with effective electromechanical coupling of 9.37% was registered for quasi-shear mode. The quasi-shear mode of the device showed better performance than quasi-longitudinal in liquid sensing application.