| In this paper, the pulse sensor made by MEMS technology has square silicon film with four P type MOSFETs channel equivalent resistances which make up of Wheatstone bridge, and the two P type MOSFETs channel equivalent resistances are located at the longitudinal orientation, and the other two are located at the transverse orientation. When the power is supplied and the pressure is applied, the two longitudinal P type MOSFETs channel equivalent resistance become bigger, the other two become smaller, so that the bridge is out of balance, the voltage output is produced, so we can use the pulse sensor to collect the slight pulse signal.This task introduces the related research of pressure sensor at home and abroad, and describes the work theory, the structure design, and the fabrication process of silicon pulse sensor. During the experiment, the I-V characteristic, and the temperature characteristic are tested; after that the static characteristic is analyzed. The experiment results indicate that the sensitivity of silicon pulse sensor is 162.26mV/100KPa, the linearity is±2.01%, the hysteresis is±0.181%, the repeatability is±0.21%, the precision is 2.029%. The silicon pulse sensor meets the design demand.This task uses the structure of P-MOSFET channel as pressure sensitive resistance to research the pulse sensor, which has the following advantages: the test signal is stabilized, the temperature characteristic is better,the sensitivity is higher, so the stability of the sensor is enhanced, the disturbance of the sensor is minimized, and we can use it to collect the slight pulse signal objectively and accurately. The process of silicon pulse sensor based on MEMS technology is compatible with IC process, which has expensive application prospect. |
