Fabrication at wafer level of miniaturized gas sensors based on SnO2 nanorods deposited by PECVD and gas sensing characteristics

SnO2 nanorods were successfully deposited on 3″ Si/SiO2 wafers by inductively coupled plasma-enhanced chemical vapour deposition (PECVD) and a wafer-level patterning of nanorods layer for miniaturized solid state gas sensor fabrication were performed. Uniform needle-shaped SnO2 nanorods in situ grown were obtained under catalyst- and high temperature treatment-free growth condition. These nanorods have an average diameter between 5 and 15 nm and a length of 160–300 nm. The SnO2-nanorods based gas sensors were tested towards NH3 and CH3OH and gas sensing tests show remarkable response, showing promising and repeatable results compared with the SnO2 thin films gas sensors.