CMOS Integrated Nanocrystalline SnO2 Gas Sensors for CO Detection

Abstract In this work, we present gas sensors based on nanocrystalline SnO 2 ultrathin films, which were integrated on microhotplate chips fabricated by CMOS technology. The gas sensitive films, with a thickness of 50nm, were deposited on the microhotplate by a spray pyrolysis process. The CMOS integrated sensor resistance was significantly decreased in the presence of carbon monoxide. A sensor response of up to 50% is achieved at an operating temperature of 375C. The microhotplate chips presented here enable 3D integration of different gas sensing systems by through-silicon-via technology. Such 3D-integrated nanosensors are promising candidates for building smart gas sensor devices for daily life applications.