A silicon resonant pressure sensor based on thermal stresses matched structures

Abstract This paper introduced a silicon resonant pressure sensor based on thermal stress-matched structures to extend the operating temperature range. The sensor designed this time consists of an SOI wafer with a pressure-sensitive diaphragm for pressure sensing and two integrated resonators, a silicon wafer for vacuum packaging, and a glass wafer for additional stress isolation. The multilayer structures were bonded together to form a thermal stress-matched part to address the problem of temperature inflection points of conventional resonant pressure sensors within broad temperature zones. Finite element analyses optimized the sensor’s pressure- and temperature-sensitive characteristics. Micromachining based on eutectic and anodic bonding to fabricate sensor chips. Characterization results indicated the developed pressure sensor can work stably in a wide temperature range of -55∼125°C and has excellent fitting accuracy exceeding ±0.01% FS., which showed a better performance than previously reported counterparts.