AN IC-COMPATIBLE POLYIMIDE PRESSURE SENSOR WITH CAPACITIVE READOUT

A capacitive differential pressure sensor has been developed. The proc ess used for the fabrication of the sensor is IC-compatible, meaning t hat the device potentially can be integrated on one chip with a suitab le signal-conditioning circuit. A sensor for a differential pressure o f +/- 1 bar has been fabricated and tested with a frequency-modulated detection circuit, and good agreement is found with the theoretical mo del of the sensor. A nominal sensitivity Delta C/C of 17% has been mea sured for a positive differential pressure of I bar. The resolution of the complete detection system is 2.5 mbar (250 Pa). (C) 1997 Elsevier Science S.A.