A Temperature-Compensated ZnO-on-Diamond Resonant Mass Sensor

This paper reports on the fabrication and measurement of ZnO-on-diamond length-extensional resonant mass sensors. Improved mass sensitivity due to the higher frequency of operation as well as lower motional impedance compared to capacitively-transduced sensors of the same type is demonstrated. Measured mass sensitivity of ~1 kHz/pg is shown at ~39 MHz operation frequency. Moreover, a small temperature coefficient of frequency (TCF) of -6 ppm/degC is achieved by incorporating a layer of silicon dioxide in the resonator structure.