The research of dual-mode film bulk acoustic resonator for enhancing temperature sensitivity

Abstract

A dual-mode film bulk acoustic resonator (DM-FBAR) temperature sensor modulated by different phosphorous-doped silica insertion layers was reported in this paper. The relative drift of the second and third resonance peaks of FBAR could improve the temperature sensitivity through the dual-mode beat frequency calculation method. The temperature sensitivity can be regulated by different the PH3 doping flow in the SiO2 insertion layer. Among the fabricated devices, FBAR with a SiO2 insertion layer doped 4 sccm PH3 has the highest temperature sensitivity of 64.8 kHz °C−1. It is discovered that the greater the Young’s modulus of the insert film changes with temperature, the higher the temperature sensitivity of DM-FBAR device. Therefore, an important technical means to improve the performance of DM-FBAR devices is using the material whose Young’s modulus is more sensitive to temperature in the future.