Thin film bulk acoustic resonators based on c-axis tilted yttrium-doped AlN for Viscosity sensors

thin film bulk acoustic resonators FBAR based on polar c-axis tilted Yttrium-doped AlN is proposed as liquid viscosity sensor. Firstly, the effect of tilting angle on the electromechanical proprieties of Yttrium-doped AlN thin film is investigated. A huge shear mode electromechanical coupling coefficient is observed in c-axis tilted AIYN films. Secondly, the electrical admittance of AlYN- FBAR is demonstrated for different Yttrium concentrations. The resonant frequencies shift down due to viscous liquid loading. The obtained results show that FBARs based on tilted c-axis AlYN thin films are very interesting for high sensitive liquid sensors.