Sensitivity improvement for CMOS-MEMS capacitive pressure sensor using double deformarle diaphragms with trenches

Abstract

This study presents a novel capacitive pressure sensor implemented by TSMC 0.18μm 1P6M CMOS process. Features of this design is to exploit double deformable sensing diaphragms to enhance the sensitivity of capacitive pressure sensor (Fig. 1a). Moreover, the sensing diaphragms with trenches can further improve the sensitivity due to stiffness reduction. The sensitivity of designed pressure sensor with trenches on double deformable electrodes is 0.26fF/kPa (within the absolute pressure range of 20kPa∼110kPa). The sensitivity is improved for 2.9-fold as compared with the single diaphragm reference design in Fig.1b.