A Resonant Low-Pressure Microsensor With Low Temperature Disturbance

This article introduces a resonant low-pressure microsensor comprising a silicon-on-insulator wafer (SOI) for low-pressure sensing, and a glass-on-silicon wafer (GOS) for vacuum package. In GOS wafer, the inclusion of silicon layer can dramatically decrease thermal mismatch between device layer in SOI and glass layer in GOS, effectively reducing temperature disturbance of the resonant low-pressure microsensor from 107 Hz/°C (with glass wafer packaging) to 26 Hz/°C (with GOS wafer packaging) based on FEA simulations. Experimental results demonstrated that the low-pressure sensitivities and temperature disturbances for the fabricated microsensors were measured as ±4 Hz/Pa and 35 Hz/°C separately. Based on pressure and temperature calibrations, higher accuracies indicated by fitting errors inside ±1.8 Pa, measurement errors inside ±4 Pa and hysteresis inside 1.6 Pa, were realized by the resonant low-pressure microsensor in the pressure and temperature ranges of 0.1-1 kPa and −40 – 80 °C, demonstrating higher performances than previous studies with wider temperature range.