A Temperature-Insensitive Resonant Pressure Micro Sensor Based on Silicon-on-Glass Vacuum Packaging

Abstract

This paper presents a temperature-insensitive resonant pressure sensor, which is mainly composed of a silicon-on-insulator (SOI) wafer for pressure measurements and a silicon-on-glass (SOG) cap for vacuum packaging. The variations of pressure under measurement bend the pressure sensitive diaphragm and regulate the intrinsic frequencies of the resonators in the device layer. While, variations of temperature cannot significantly change the intrinsic frequencies of the resonators, due to the SOG cap to offset generated thermal stress. Numerical simulations, based on finite element analysis, were conducted to calculate the residual thermal stress and optimize the sensing structures. Experimental results show that the Q-factors of the resonators are higher than 16,000, with a differential pressure sensitivity of 11.89 Hz/kPa, a nonlinearity of 0.01% F.S and a low fitting error of 0.01% F.S with the pressure varying from 100 kPa to 1000 kPa. In particular, a temperature sensitivity of ~1 Hz/°C was obtained in the range of −45 °C to 65 °C, which is one order of magnitude lower than the previously reported counterparts.

Si-based MEMS resonant sensor: A review from microfabrication perspective

“…The minimum feature sizes that can be obtained are up to 10 µm [111]. Yan et al proposed three photo-lithographic steps to release the resonator structure and a 140 µm pressure sensitive diaphragm was etched on Si handle layer by DRIE technique with the help of patterned PR mask [112]. Once the design pattern is transferred, the resist is usually stripped off.…”

A Compact Optical MEMS Pressure Sensor Based on Fabry–Pérot Interference

“…Therefore, the monitor of the wind pressure is necessary to ensure the stable operation of the transmission line tower [3], and the pressure sensor can be selected to monitor the wind pressure. At present, the pressure sensors are divided into the types of piezoresistive [4], piezoelectric [5], capacitive [6], resonant [7], and optical pressure sensors [8] according to the detection method. Among them, piezoresistive, piezoelectric, resonant, and capacitive pressure sensors are popular due to their simple structure and low cost [9][10][11][12].…”

Effects of Resonator Shape on Nonlinear Resonant Frequencies of a Microresonant Pressure Sensor

“…Xiang et al introduced a resonant pressure microsensor in which the silicon islands are deployed on an SOI wafer to improve the equivalent sti ness and structural stability of the pressure-sensitive diaphragm [17]. Zhao et al and Yan et al developed temperature-insensitive silicon resonant pressure sensors with very-low-frequency temperature coe cients [18,19]. Zamanzadeh et al proposed a resonant pressure sensor that provided a wider range of tunability and sensing range and a simpli ed signal-processing circuit [20].…”