Abstract

This paper described an infrared (IR) radiation sensor based on Film Bulk Acoustic Resonator (FBAR). The resonant frequency of the FBAR decreased linearly when there was IR (peak wavelength at 780 nm) illumination on the device. The sensing mechanism was attributed to the temperature-dependent Youngs modulus of the resonator material (ZnO), which subsequently shifted the resonant frequency. The noise equivalent temperature difference (NETD) and the detection limit for 780 nm IR were 16 mK at 25 °C and 2.9 μW/mm2, respectively. This study has proven the feasibility of detecting IR using ZnO film based FBAR.

Keywords: Film bulk acoustic resonator, infrared radiation