A high-sensitive ultra-thin MEMS capacitive pressure sensor

摘要

This paper reports an ultra-thin MEMS capacitive pressure sensor with high pressure sensitivity of better than 150aF/Pa, and small die size of 1.0mm × 1.0mm × 60µm. It is able to detect ambient pressure change with a resolution of 0.025% in a pressure range +/−3.5KPa. This capacitive pressure sensor decouples the pressure sensing from its capacitance sensing by using a hermetically sealed capacitor that is electrically isolated but mechanically coupled with a pressure sensing diaphragm such that a large dynamic range and high pressure sensitivity can be readily achieved. Because the capacitor is hermetically sealed in a cavity, this capacitive pressure sensor is also immune to measurement media and EMI (Electromagnetic Interference) effects.