Fabrication and Characteristics of Silicon Bridge Magnetic Sensor Based on Nano-Polysilicon TFTs

Abstract

A silicon bridge magnetic sensor based on nano-polysilicon TFTs is presented in this paper.It adopted four nano-polysilicon TFTs on the center of every squared silicon membrane edge to forma Wheatstone bridge, and then its squared silicon membrane center was sticked by ferromagnetic material.The sensor simulation was realized by adopting ANSYS software. The simulation results showthat based on the piezoresistive effect, the measurement to the external magnetic field can be achieved.According to the simulation results, we designed and fabricated the silicon bridge magnetic sensor byCMOS technology and MEMS technology. The experimental results show that when supply voltageof the sensor is 5.0 V, its full range (4.0 kGs) output voltage is 10.97 mV, and magnetic sensitivity is1.44 mV/kGs.

An Integrated Pressure and Magnetic Field Sensor Based on Piezoresistance Effect

“…Basic Structure. Figure 1 shows the basic structure of integrated sensor consisted of a C-type silicon cup, ferromagnetic material and Wheatstone bridge [7,8]. The Wheatstone bridge composed of four MOSFET channel resistances (R 1 , R 2 , R 3 and R 4 ) locating on the every edge center of squared silicon membrane is used as an insensitive element of sensor, and the MOSFET channel resistances locating on the regions of maximum stresses are used as piezoresistances.…”