The sensitivity enhancement for the radiation sensor based on Film Bulk Acoustic-Wave Resonator

This paper describes the new design and material selection used to improve the sensitivity of ionizing radiation sensing with a zinc oxide based Film Bulk Acoustic-Wave Resonator (FBAR). Prior results demonstrated that the parallel resonant frequency of the FBAR decreased after irradiation due to radiation-induced charge trapping in the SiN. Here, by employing Plasma Enhanced Chemical Vapor Deposited (PECVD) silicon nitride (SiN) within a two layer SiN configuration, we were able to increase the sensitivity by over two orders of magnitude. The maximum sensitivity of 2300 kHz/krad was demonstrated and is the highest radiation sensitivity of resonant sensors known to the authors.