Gas Sensing Characterisation of CMOS Integrated Nanocrystalline SnO2 – Au Thin Films☆

Abstract Conductometric measurements were performed on a CMOS integrated SnO 2 – Au functionalized gas sensor. The sensor material was deposited by spray pyrolysis at 400 °C upon a microhotplate (a CMOS integrated structure to adjust the sensor's temperature). The sensing layers were structured by photolithography and ion etching. The functionalization of the SnO 2 layers was conducted by evaporation of a 2 nm thin gold film. In a subsequent step the sensing layers were tempered at 400 °C, which resulted in the formation of Au nanoparticles. The sensor performance is evaluated for ethanol, a hydrocarbon-mix (acetylene, ethane, ethene, and propene) and two relative humidity levels.