Ultra-High Sensitivity Surface-Micromachined Capacitive Differential Pressure Sensor for Low-Pressure Applications

An ultra-high sensitivity surface-micromachined capacitive differential pressure sensor and capacitance bridge readout circuit, with amplitude balancing for differential low-pressure gas measurement applications, was designed, fabricated, and characterized. The sensor membrane has a diameter of 800 mu m with a thickness of 1 mu m and the chip size is 1.5 x 2 x 0.6 mm(3). The characterized sensor pressure range is 0-2000 Pa, with a full-scale capacitance difference span of 0.95 pF. Typical pressure error within the pressure range of 0-2000 Pa is +/- 0.5%, and the temperature coefficient is 0.044%/degrees C, both respectively from the pressure reading.

Automated summary

An ultra-high sensitivity surface-micromachined capacitive differential pressure sensor and capacitance bridge readout circuit for low-pressure gas measurement applications was designed and fabricated. The sensor membrane has a diameter of 800 mu m with a thickness of 1 mu m, and the pressure range is 0-2000 Pa.