SILICON PRESSURE SENSOR WITH INTEGRATED BIAS STABILIZATION AND TEMPERATURE COMPENSATION

A piezoresistive pressure sensor for relative or differential pressure applications has been developed. The use of a 10-mu-m thick bossed membrane provides high sensitivity (typically 3.3-mu-V/V Pa) in the low-pressure range (0-60 hPa). Adaptation of sensor fabrication to a triple-diffusion bipolar process by application of an electrochemical etch-stop at a diffused n-type layer on a p-substrate allows monolithic integration of two different conditioning circuits operating with battery voltages of 12 to 20 V. Both circuits provide bias stabilization and temperature compensation for temperatures between -30 and +90-degrees-C. Thus the possibility of sensor fabrication by using standard IC technologies is demonstrated.