Non-SOI (111) Wafer Single-Side Microfabrication of Silicon-Based Resonant Structure Inside Vacuum Chamber for Tiny-Size, High-Performance and Low-Cost Resonant Differential Pressure Sensors

Reported is a tiny-size and high-sensitive resonant pressure sensor for high-performance and low-cost volume production. Compared to the previously reported SOI-based resonant pressure sensor, two H-shape silicon-based resonators are constructed on the pressure-sensing diaphragm and then housed inside vacuum chamber by using polysilicon. Benefited to the monolithic manufacturing process on a non-SOI (111) wafer and without wafer bonding needed, the fabricated sensor chip-size is as small as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4.0 \text{mm }\times 4.0\mathrm{m}$</tex>. According to the simulation results, a high sensitivity of 276.53 Hz/kPa (without amplification) will be measured within the measurement range of 160 kPa.