Wireless magnetostrictive type inductive sensing CMOS-MEMS pressure sensors

Abstract

This study demonstrates the wireless magnetostrictive type inductive sensing CMOS-MEMS pressure sensors using the TSMC 0.18μm 1P6M process. Features of this study are: (1) High sensitivity pressure sensors are realized based on the inverse-magnetostrictive sensing principle; (2) metal and dielectric layers of CMOS process are employed to form the magnetic coil and sensing diaphragm respectively; (3) additional magnetostrictive CoFeB film was deposited and patterned by the shadow sputtering; (4) wireless sensing is available by the external reading coil. Experiments show sensors with gauge-factor ranging 480∼1100 are achieved, and wireless sensing capability is also demonstrated.