An Integrated Pressure and Magnetic Field Sensor Based on Piezoresistance Effect

Abstract

An integrated pressure and magnetic field sensor based on piezoresistance effect is proposedin this paper. The integrated sensor is composed of a C-type silicon cup, ferromagnetic materialand Wheatstone bridge constructed by four metal oxide semiconductor field effect transistors(MOSFETs) channel resistances as piezoresistances. Based on the piezoresistance effect of channelresistances, the measurement to the external pressure P and magnetic field B can be achieved by thesensor. Through using complementary metal oxide semiconductor (CMOS) technology and microelectromechnicalsystem (MEMS) technology, the sensor chip was designed and fabricated on <100>orientation silicon substrates, locating the ferromagnetic material on its squared silicon membranecenter. The experimental results show that when supply voltage of the sensor is 2.0 V, the pressuresensitivity of sensor is 0.39 mV/kPa (B=0 T), and the magnetic field sensitivity of sensor is 1.48 mV/T(P=0 kPa).