A fully CMOS compatible integrated absolute pressure sensor

This paper presents a fully CMOS technology integrated capacitive absolute pressure sensor with on-chip switched capacitor integration circuitry for barometric applications. The overall sensor system process merges CMOS IC technology and a bulk micromachining process utilized after the pre-CMOS process, thus it does not change the IC technology sequence. The sensor consists of a switched capacitor interface readout circuit, a sandwich-structured capacitive transducer with a composite-membrane and a reference capacitor, all integrated on the same chip by a standard CMOS process.