Miniature integrated capacitive pressure sensor

A miniature integrated silicon capacitive pressure sensor has been fabricated. The pressure sensor consists of a Pyrex glass and a silicon chip. A silicon diaphragm and a CMOS capacitance to frequency converter are integrated on the same silicon chip. The silicon chip is hermetically sealed by the Pyrex glass using anodic bonding in wafer process. The sensor capacitor is formed by the silicon diaphragm and a counter metal electrode on the Pyrex glass. The output frequency is detected by the current change in power line. The pressure sensor has higher sensitivity, lower temperature drift and lower power consumption than the conventional piezoresistive pressure sensor.