Thin Film Plate Wave Resonant Sensor for Pressure and Gravimetric Measurements

AbstractThin film plate acoustic resonators (FPAR) devices operating in the lowest order symmetric Lamb wave mode (S0), the first order asymmetric Lamb wave mode (A1) and the first order symmetric Lamb wave mode (S1), propagating in c-oriented aluminum nitride (AlN) membranes on Si were fabricated and tested for their sensitivities to pressure and mass. Systematic data on frequency shifts versus rigid mass (layer) thickness and ambient pressure variations are presented for the different Lamb wave resonances. Further the ability to work in liquid environment of the S0, A1 and S1 modes, respectively, has been tested in view of Bio-sensor applications