Assessment of Bulk Acoustic Wave Based Solidly Mounted Resonator (BAW-SMR) as Ozone Sensor Using ITO Sensitive Layer

In this paper, a highly sensitive ozone sensor based on a Bulk Acoustic Wave based Solidly Mounted Resonator (BAW-SMR) is reported using Indium Tin Oxide (ITO) as ozone-sensitive material on the top of the resonator. The resonant frequency of the resonator is 4944 MHz and due to 4 ppb ozone gas adsorption, the frequency downshifts by 750 kHz and the resultant sensitivity of the sensor is 187.5 kHz/ppb. In addition to it optimized number of Bragg pairs ((Mo/SiO
2
) is also investigated. The ozone sensor modeling is done by Finite Element Method (FEM) model and the Bragg reflector modeling is done by the Mason model respectively. A comparison of the proposed ozone sensor to other acoustic resonator based ozone sensors is also presented in this paper.