Resonate frequency research on material characteristics of FBAR temperature sensor

The paper investigates the resonate frequency characteristics of film bulk acoustic resonator (FBAR) temperature sensor, including resonate frequency, effective electromechanical coupling coefficient (k
_eff
²
) and the effect of temperature on resonate frequency. The theoretical calculation formula of resonant frequency related to thickness and temperature is derived and it is verified by means of finite element simulation. The performance of FBAR composed of AlN, ZnO, PZT piezoelectric film and MO, Al, Au electrode is discussed and compared, respectively. The temperature coefficient of frequency (TCF) of FBAR temperature sensor composed of AlN and ZnO is obtained, respectively. The TCF of FBAR composed of AlN piezoelectric film is -19.380ppm, and the TCF of FBAR composed of ZnO piezoelectric film is -62.756ppm.