Ultra-small micro pressure sensor chip design and fabrication featuring high-sensitivity and good-linearity

Ultra-small micro pressure sensors are demanded in dynamic performance research of airplanes, missiles and other mechanical movements in aerodynamics. In this study, a novel two island-beam-diaphragm structural sensor chip is designed to improve the sensitivity and linearity simultaneously. Two islands are introduced into the back side of the chip to fulfill the requirement of stress concentration. The chip is fabricated with silicon micromachining technology and calibrated after packaging into a pressure sensor. The resulting sensors perform well. The sensitivity of the sensor is 1.60 mV/V/100 Pa, higher than the designed 1.48 mV/V/100 Pa. Nonlinearity values at 0.04 %FS and repeatability and hysteresis uncertainty value at 0.01 %FSO and 0.05 %FSO, respectively. The temperature coefficient of sensitivity and temperature coefficient of offset is −0.93 × 10⁻³/°C FSO and 0.86 × 10⁻³/°C FSO. The accuracy is 0.04 %FSO. Extremely high over-pressure capability is achieved due to the small island for over-range protection.